JP7623567B2 - Optometry Equipment - Google Patents

Description

This disclosure relates to an optometry device for measuring a subject's eye.

There are known subjective eye examination devices, visual acuity testing devices, and the like, which are capable of testing the subject's eye. For example, a subjective eye examination device can measure the optical characteristics of the subject's eye by placing an optical element (e.g., a spherical lens, a cylindrical lens, etc.) in front of the subject's eye and presenting a test target to the subject through the optical element (Patent Document 1). Also, for example, a visual acuity testing device can measure the visual acuity of the subject's eye by having the subject look into a target window to confirm the test target (Patent Document 2).

Japanese Patent Application Publication No. 5-176893 JP 2000-287926 A

In tests using subjective eye examination devices or visual acuity testing devices, subjects can respond by feel, even if they cannot see the test target. For example, even if they are not gazing at the Landolt ring, they can respond by intuition about the direction of the slits in the Landolt ring. If the answers given when the subject properly sees the test target are mixed with answers given by feeling in this way, it becomes difficult to obtain accurate test results for the subject's eye.

In view of the above-mentioned conventional techniques, the technical objective of the present disclosure is to provide an optometry device that can improve the accuracy of examining the subject's eye.

In order to solve the above problems, the present disclosure is characterized by having the following configuration:

The eye examination device according to the present disclosure is an eye examination device for presenting a test optotype to an eye to be examined and examining the eye to be examined, comprising: an answer input means for inputting the subject's interpretation result for the test optotype; an answer acquisition means for acquiring answer information regarding the interpretation result based on an input signal from the answer input means; an anterior eye image acquisition means for acquiring an anterior eye image of the eye to be examined; an eye gaze information acquisition means for acquiring gaze information regarding the gaze of the eye to be examined based on the anterior eye image; and a change control means for changing the presentation state of the test optotype to the eye to be examined based on the answer information and the gaze information, wherein a detection area is provided for each of the test optotypes for detecting a coincidence between the position of the gaze and the position of the test optotype, and the gaze information acquisition means acquires, as the gaze information, a determination result of whether or not the eye to be examined is gazing at the test optotype based on a first timing when the input signal is obtained from the answer input means and a second timing when the position of the gaze is included in the detection area .

FIG. 1 is an external view of a subjective optometry device. FIG. 4 is a schematic diagram of a measurement unit. FIG. 2 is a front view of the inside of the subjective optometry device. FIG. 2 is a side view of the inside of the subjective optometry device. FIG. 2 is a top view of the inside of the subjective optometry device. FIG. 1 is an example of an anterior eye image. 1 is an example of a display. 11 is a flowchart showing an example of a flow of subjective measurement. 13 is a flowchart showing an example of change control in obtaining a highest visual acuity value. 13 is a flowchart showing an example of change control in acquiring the presence or absence of adjustment. FIG. 1 is an external view of a visual acuity testing device. 2 is a schematic diagram of the right-eye optical system of the vision testing device as seen from the right side. FIG. 1 is a schematic diagram of a right-eye optical system and a left-eye optical system of a visual acuity testing device as viewed from above. 13 is a flowchart showing an example of change control in the visual acuity testing apparatus.

＜Overview＞
An embodiment of an optometric device according to the present disclosure will be described. The items grouped in <> below may be used independently or in conjunction with each other.

The optometry device of this embodiment is a device for presenting a test target to the subject's eye and testing the subject's eye. Note that this technology can be applied to any device that presents a test target to the subject's eye.

<How to enter answers>
The optometry apparatus of the present embodiment may further include a response input unit for inputting the subject's interpretation of the test optotype.

For example, the answer input means may be a means for the subject to input the results of his/her interpretation of the test optotype. In this case, the answer input means may be an operating means such as a lever switch or a push button switch (e.g., the subject controller 8 and the subject controller 303). Also, the answer input means may be a voice input means such as a microphone. Also, the answer input means may be a detection means for detecting the movement of the subject's gaze or gestures.

For example, the answer input means may be a means for an examiner to input the results of the subject's interpretation of the test optotype on behalf of the examiner. In this case, the answer input means may be at least one of an operation means, a voice input means, a detection means, etc.

The subject's interpretation of the test optotype may be any result that indicates whether or not the subject interpreted the test optotype. For example, if the test optotype has directionality, it may be the result of answering the direction of the test optotype. As one example, it may be the result of answering in which direction the gap in the Landolt ring optotype is located.

<Response information acquisition means>
The optometry apparatus of the present embodiment may include an answer acquisition unit (for example, the control unit 10 and the control unit 340). The answer acquisition unit acquires answer information on the interpretation result based on an input signal from the answer input unit. The answer acquiring means may acquire an input signal from the answer input means as the answer information. For example, in this case, the answer acquiring means may acquire a signal indicating that a predetermined push button switch among a plurality of push button switches has been pressed. Alternatively, the answer acquiring means may acquire a signal representing the direction of movement of the subject's line of sight as the answer information. Of course, the answer acquiring means may acquire a detection signal by the answer input means as the answer information. The detected signal may be acquired as response information.

The answer acquisition means may also acquire, as answer information, conversion information obtained by converting an input signal based on an input signal from the answer input means. For example, in this case, conversion information obtained by converting the pressing of a specific push button switch into the subject's answer (for example, the direction of the gap in the Landolt ring target being "right") may be acquired as answer information. Of course, the answer acquisition means may also acquire, as answer information, conversion information obtained by converting a detection signal based on a detection signal from the answer input means. For example, in this case, conversion information obtained by converting the direction of movement of the subject's gaze into the subject's answer may be acquired as answer information.

<Anterior segment image acquisition means>
The optometry apparatus of this embodiment may include an anterior eye image acquiring means (for example, the control unit 10). The anterior eye image acquiring means acquires an anterior eye image of the subject's eye. The anterior eye image may be an image including a bright spot image projected onto the subject's eye, or may be an image not including a bright spot image. It may be a single image, or it may be two images in which the left and right eyes to be examined are photographed respectively.

The ophthalmic examination apparatus may be provided with an anterior eye imaging means (e.g., an observation optical system 50 and an anterior eye observation unit 330) that images the anterior eye of the subject's eye. For example, the anterior eye imaging means may be provided integrally with a component that constitutes the ophthalmic examination apparatus (for example, an optical system). In this case, the anterior eye image acquisition means may acquire an anterior eye image as the imaging result of the anterior eye imaging means.

Of course, the anterior eye image acquisition means may acquire an anterior eye image by receiving an image captured by another device having a function for capturing an image of the anterior eye of the subject eye. For example, the image captured by a wearable device (for example, a glasses-type wearable terminal, a head-mounted display, etc.) may be acquired as an anterior eye image.

<Line-of-sight information acquisition means>
The optometry apparatus of the present embodiment may include a gaze information acquiring means (for example, the control unit 10 and the control unit 340). The gaze information acquiring means acquires gaze information related to the gaze of the subject's eye based on an anterior eye image. Get the.

The gaze information acquisition means may acquire the eye position of the subject eye as gaze information by performing image analysis on the anterior eye image. For example, in this case, the gaze information acquisition means may detect the pupil center and Purkinje image from the anterior eye image, and acquire the eye position based on the position of the pupil center and the position of the Purkinje image. Note that in addition to the position of the pupil center and the position of the Purkinje image, the corneal curvature radius and the anterior chamber depth may be used to acquire the eye position.

The gaze information acquisition means may acquire the gaze position of the subject's eye as gaze information by performing image analysis on the anterior eye image. For example, the gaze position of the subject's eye may be acquired as a predetermined point, or as an area centered on the predetermined point. For example, in this case, the gaze information acquisition means may detect at least one of the pupil center and the corneal apex from the anterior eye image, and acquire the gaze position based on at least one of the pupil center position and the corneal apex position. As an example, the gaze position may be detected by inferring the gaze direction from the pupil center position or the corneal apex position. As another example, the gaze position may be detected by inferring the gaze direction from the deviation between the pupil center position and the corneal apex position. The gaze position may also be acquired by using electrooculography, corneal reflex method, scleral reflex method, etc.

In addition, the gaze information acquisition means may acquire at least one of the eye position and gaze position of the subject's eye as gaze information related to the gaze of the subject's eye.

The gaze information acquisition means may acquire, as the gaze information, the result of the determination of whether or not the subject's eye is gazing at the test target. In this case, the gaze information acquisition means may determine whether or not the subject's eye is gazing at the test target by determining whether or not the eye position of the subject's eye exceeds a predetermined threshold value associated with the position of the test target. In addition, in this case, the gaze information acquisition means may determine whether or not the subject's eye is gazing at the test target by determining whether or not the position of the gaze of the subject's eye overlaps at least a part of the test target. Of course, it may be determined whether or not the subject's eye is gazing at the test target by taking into consideration both such a determination result for the eye position of the subject's eye and such a determination result for the position of the gaze of the subject's eye. This makes it easy to distinguish whether the subject's answer was given while looking at the test target or not.

For example, in this embodiment, a detection area may be provided for each test optotype to detect whether the position of the gaze of the test eye coincides with the position of the test optotype. For example, the detection area may be a detection area for detecting whether the position of the gaze of the test eye coincides with at least one of the positions (presentation position) in the left-right and up-down directions on the test optotype. Note that, for example, the detection area may be provided as a different area for each test optotype based on at least one of the distance from the test eye to the test optotype (i.e., test distance), the type of test optotype, the visual acuity value of the test optotype (in other words, the size of the test optotype), etc.

The detection area may be provided as an area including at least a portion of the test optotype. For example, the detection area may be an area including the entire test optotype. In this case, the detection area may be a predetermined area based on the center of the test optotype. For example, the detection area may be an area including a portion of the test optotype. In this case, the detection area may be a predetermined area based on a predetermined portion of the test optotype (for example, the gap portion of the Landolt ring optotype).

When a detection area is provided for each test optotype, the gaze information acquisition means may acquire a judgment result that judges whether or not the subject's eye is gazing at the test optotype, based on whether or not the gaze position is included in the detection area. For example, in this case, the gaze information acquisition means may judge whether or not the subject's eye is gazing at the test optotype, taking into account the time during which the gaze position is included in the detection area. As an example, it may be judged that the test eye is gazing at the test optotype when the gaze position is included in the detection area for a certain period of time or more. This clarifies the judgment criteria for gazing at the test optotype, and makes it easy to obtain a judgment result.

Furthermore, the gaze information acquisition means may acquire a judgment result that judges whether or not the subject's eye is gazing at the test target, taking into consideration the timing of obtaining the subject's answer information. This makes it possible to obtain a judgment result with high accuracy that excludes cases where the gaze coincides with the test target.

For example, the gaze information acquisition means may acquire a determination result of whether or not the subject's eye is gazing at the test target based on whether or not the gaze position was included in the detection area when an input signal was obtained from the answer input means. For example, it may be determined that the subject is gazing at the test target when a first timing at which an input signal was obtained from the answer input means coincides with a second timing at which the gaze position was included in the detection area. Note that the coincidence of the first timing and the second timing also includes a state in which the first timing and the second timing are approximately the same. Also, for example, the gaze information acquisition means may determine that the subject is gazing at the test target when the second timing is included between the first timing and a predetermined timing prior to the first timing.

<Change Control Means>
The eye examination apparatus of this embodiment may include a change control acquisition means (e.g., the control unit 10 and the control unit 340). The change control means changes the presentation state of the test target to the subject's eye based on the answer information acquired by the answer acquisition means and the gaze information acquired by the gaze information acquisition means. This allows for accurate test results to be obtained that take into account the position and direction of the gaze of the subject's eye as well as the correctness of the subject's answer.

The change control means may change the presentation state of the test optotypes for the subject's eye to a state in which the test optotypes are different from each other by controlling the optotype presentation means described below. For example, at least one of the direction, visual acuity value, type, etc. of the test optotypes may be different before and after the presentation state is changed. This allows the test optotypes to be appropriately put into an appropriate state.

The change control means may change the presentation state of the test optotype for the subject's eye to a state in which the presentation areas in which the test optotype is presented, described below, are different, by controlling the optotype presenting means described below. In other words, the presentation position of the test optotype may be different before and after the presentation state is changed. The line of sight of the subject's eye moves significantly as the presentation position of the test optotype is changed randomly, making it easier to obtain accurate line of sight information. If the optotype presenting means is a display, the presentation position of the test optotype can be easily changed.

The change control means may change the state of presentation of the test target to the subject's eye to a state in which the correction power for correcting the subject's eye is different by controlling the correction means described below. For example, at least one of the spherical power, cylindrical power, astigmatism axis angle, etc. may be different before and after the presentation state is changed. This allows the correction power to be appropriately set to an appropriate state.

Of course, the change control means may change the presentation state of the test optotypes for the subject's eyes to at least one of the following states: the test optotypes are different from each other, the presentation positions of the test optotypes are different from each other, and the correction powers of the subject's eyes are different from each other.

<Target Presentation Means>
The eye examination apparatus of the present embodiment includes a target presenting means for emitting a target light beam toward the subject's eye, thereby presenting a test target to the subject's eye.

For example, the optotype presenting means may be a display (e.g., display 61). For example, the optotype presenting means may be a light source and a DMD (Digital Micromirror Device). For example, the optotype presenting means may be a light source and an optotype plate (e.g., an optotype illumination lamp 323 and an optotype plate 321). In this case, the light source may be a visible light source, and the optotype plate may be a disk having a plurality of test optotypes. For example, on the optical path along which the optotype light beam is guided to the subject's eye, the optotype plate is rotated by a motor or the like, so that the test optotypes are switched and positioned relative to the subject's eye.

The optotype presenting means may be provided so as to share at least a portion of the optotype presenting means for the right eye and the optotype presenting means for the left eye. The optotype presenting means may also be provided in a pair on the left and right, each having an optotype presenting means for the right eye and an optotype presenting means for the left eye. In this case, the optotype presenting means for the right eye and the optotype presenting means for the left eye may be made of the same material. In this case, the optotype presenting means for the right eye and the optotype presenting means for the left eye may be made of at least a portion of different materials.

The optotype presenting means may have one presentation area capable of presenting the test optotype. The optotype presenting means may also have multiple presentation areas capable of presenting the test optotype. For example, the multiple presentation areas may be areas that partially overlap.

For example, when the optotype presenting means is a display, the display surface of the display may be set as one display area, thereby setting one presentation area for the test optotype. Also, the display surface of the display may be divided into multiple display areas, thereby setting multiple presentation areas for the test optotype. Also, when the optotype presenting means is a light source and optotype plate, the shape of a masking member that masks part of the optotype plate may be changed, thereby setting one or multiple presentation areas for the test optotype. As an example, the masking member may be a disk with an opening, or may double as part of the housing.

The target light beam from the target presenting means may be directly guided to the subject's eye. That is, the target light beam may be guided without passing through various optical elements (such as lenses, mirrors, etc.). The target light beam from the target presenting means may be indirectly guided to the subject's eye. That is, the target light beam may be guided through various optical elements. In this case, the target light beam may be guided through various optical elements constituting the light projecting optical system (e.g., the light projecting optical system 60), the correction optical system (e.g., the correction optical system 80), etc.

<Correction measures>
The optometry apparatus of the present embodiment includes a correction unit that changes the optical characteristics of the target light beam in order to change the correction power for correcting the eye to be examined. For example, the optical characteristics of the target light beam may be at least one of a spherical power, a cylindrical power, an astigmatism axis angle, and the like.

The corrective optical system may be configured to change the optical characteristics of the visual target light beam.

As an example, the correction optical system may have an optical element, and the optical characteristics of the visual target light beam may be changed by controlling the optical element. For example, the optical element may be at least one of a spherical lens, a cylindrical lens, a cross cylinder lens, a rotary prism, a wavefront modulation element, a variable focus lens, and the like. Of course, the optical element may be different from these.

As another example, the correction optical system may change the optical characteristics of the visual target light beam by optically changing the presentation position (presentation distance) of the visual target relative to the subject's eye. In this case, the visual target presenting means may be moved in the optical axis direction, an optical element (e.g., a spherical lens, etc.) arranged in the optical path may be moved in the optical axis direction, or an optical element may be inserted or removed in the optical path. Of course, a combination of two or more of these configurations may also be used.

As another example, the correction optical system may have an optical element disposed between an optical member for guiding the visual target light beam from the light projection optical system toward the subject's eye and the visual target presenting means, and the optical element may be controlled to change the optical characteristics of the visual target light beam. In other words, the correction optical system may be a phantom lens refractometer (phantom correction optical system).

The corrective means may be provided so as to share at least a portion of the right eye corrective means and the left eye corrective means. The corrective means may also be provided in a pair on the left and right, each having a right eye corrective means and a left eye corrective means. In this case, the right eye corrective means and the left eye corrective means may be made of the same material. In this case, the right eye vision corrective means and the left eye vision corrective means may be made of at least a portion of different materials.

The optometry device of this embodiment may be a subjective optometry device that measures the optical characteristics of the subject's eye by placing an optical element in front of the subject's eye and presenting the subject with a test target via the optical element. The optometry device may also be a visual acuity testing device that measures the visual acuity of the subject's eye by having the subject look into a target window to confirm the test target. Of course, the optometry device may be a different device.

For example, when the eye examination device is a visual acuity testing device, the visual acuity testing device may have a housing that houses an optotype presenting means, and an optotype window that is provided in the housing and allows the test optotype presented inside the housing to be viewed from inside the housing. In this case, the answer input means is used as a means for the subject to input the result of interpreting the test optotype by peering into the optotype window, and the change control means may change the presentation state of the test optotype to the subject's eye based on the correctness or incorrectness of the interpretation result as answer information and line of sight information. For example, the visual acuity testing device may be provided with such a configuration to automatically test the visual acuity of the subject's eye.

First Example
An example of the optometry apparatus according to this embodiment will be described.

The following describes an example of a subjective eye examination device that allows subjective measurement of the optical characteristics of the subject's eye.

Figure 1 is an external view of a subjective optometry device 100. For example, the subjective optometry device 100 includes a housing 2, a presentation window 3, a forehead rest 4, a chin rest 5, an examiner controller 6, a subject controller 8, an imaging unit 9, etc.

The housing 2 contains inside it the measurement unit 7, deflection mirror 91, reflection mirror 94, concave mirror 95, etc., which will be described later. The presentation window 3 is used to present the visual target to the subject's eye E. The forehead rest 4 is used to keep the distance between the subject's eye E and the device constant. The chin rest 5 is used to keep the distance between the subject's eye E and the device constant.

The examiner's controller 6 includes a switch section 6b, a monitor 6a, etc. The switch section 6b inputs signals for performing various settings (e.g., starting measurement, etc.). The monitor 6a displays various information (e.g., measurement results of the subject's eye E, etc.). The monitor 6a may function as a touch panel that also serves as the switch section 6b. Signals from the examiner's controller 6 are output to the control section 10 by wired or wireless communication.

The subject controller 8 includes an answer lever 8a, an answer button 8b, etc. The answer lever 8a is used when the subject inputs the result of interpreting the presented test optotype. For example, signals in four directions (up, down, left, and right) corresponding to the directions of the slits in the Landolt ring optotype can be input by tilting the lever. The answer button 8b is used when the subject cannot interpret the presented test optotype. The signal from the subject controller 8 is output to the control unit 10 by wired or wireless communication.

The imaging unit 9 is used to capture an image of the subject's face. The imaging unit 9 includes an imaging optical system (not shown). The imaging optical system may be composed of an imaging element and a lens.

<Measurement section>
The measurement unit 7 includes a left eye measurement unit 7L and a right eye measurement unit 7R. In this embodiment, the left eye measurement unit 7L and the right eye measurement unit 7R are made of the same material. Of course, each measurement unit may be made of at least a part of a different material.

Figure 2 is a schematic diagram of the measurement unit 7. In Figure 2, the measurement unit 7 is exemplified by the left eye measurement unit 7L. For example, the left eye measurement unit 7L includes a subjective measurement optical system 20, a first target projection optical system 30, a second target projection optical system 40, an observation optical system 50, and the like. Note that the left eye measurement unit 7L may further include an objective measurement optical system, for example.

<Subjective Measuring Optical System>
The subjective measurement optical system 20 is used as part of a subjective measurement unit that subjectively measures the optical characteristics of the subject's eye E. In this embodiment, the ocular refractive power is measured as the optical characteristic of the subject's eye E. In addition to the ocular refractive power, contrast sensitivity, binocular vision function (e.g., amount of heterophoria, stereoscopic vision function, etc.), etc. may be measured as the optical characteristic of the subject's eye E. For example, the subjective measurement optical system 20 is composed of a light projection optical system 60, a correction optical system 70, etc.

<Light projection optical system>
The light projection optical system 60 projects a visual target light beam toward the subject's eye E. For example, the light projection optical system 60 includes a display 61, a light projection lens 62, a light projection lens 63, a reflecting mirror 64, an objective lens 65, a dichroic mirror 66, a dichroic mirror 67, and the like.

A visual target (fixation target, test target, etc.) is displayed on the display 61. The visual target light beam emitted from the display 61 passes through the optical components from the light projecting lens 62 to the dichroic mirror 67 in order, and is projected onto the subject's eye E.

<Corrective optical system>
The correction optical system 70 is disposed in the optical path of the light projection optical system 60. The correction optical system 70 changes the optical characteristics of the visual target light beam emitted from the display 61. For example, the correction optical system 70 includes an astigmatism correction optical system 80, a drive mechanism 75, and the like.

The astigmatism correcting optical system 80 is used to correct the cylindrical power and astigmatism axis angle of the subject's eye E. The astigmatism correcting optical system 80 is disposed between the projector lens 62 and the projector lens 63. The astigmatism correcting optical system 80 is composed of two positive cylindrical lenses 81a and 81b with the same focal length. The cylindrical lenses 81a and 81b are each independently rotated around the optical axis L1 by the drive of the rotation mechanisms 82a and 82b.

In this embodiment, the astigmatism correcting optical system 80 is described using cylindrical lenses 81a and 81b as an example, but is not limited to this. The astigmatism correcting optical system 80 may be configured to correct the cylindrical power, astigmatism axis angle, etc. As an example, a corrective lens may be inserted and removed from the optical path of the projection optical system 60.

The drive mechanism 75 is composed of a motor and a slide mechanism. The drive mechanism 75 moves the display 61 in the direction of the optical axis L1. As a result, in the subjective measurement, the presentation distance of the optotype to the test eye E can be optically changed to correct the spherical power of the test eye E. That is, a configuration in which the display 61 is moved in the direction of the optical axis L1 is used as a spherical correction optical system for correcting the spherical power of the test eye E, and the spherical power of the test eye E is corrected by changing the position of the display 61. The spherical correction optical system may be configured to correct the spherical power by arranging a number of optical elements in the optical path. The spherical correction optical system may also be configured to correct the spherical power by arranging a lens in the optical path and moving the lens in the optical axis direction.

The driving mechanism 75 may also move a driving unit 76 that synchronizes the display 61 in the subjective measurement optical system 20 with some of the optical components that make up the objective measurement optical system.

<First target projection optical system and second target projection optical system>
The first target projection optical system 30 and the second target projection optical system 40 are disposed between a dichroic mirror 67 and a deflection mirror 91 described later. The first target projection optical system 30 emits near-infrared light for projecting an alignment target at infinity onto the cornea of the subject's eye E. The second target projection optical system 40 is disposed at a position different from the first target projection optical system 30, and emits near-infrared light for projecting an alignment target at finite distance onto the cornea of the subject's eye. The near-infrared light (alignment light) emitted from the second target projection optical system 40 is also used as anterior segment imaging light for imaging the anterior segment of the subject's eye by the observation optical system 50.

<Observation optical system>
The observation optical system (imaging optical system) 50 includes a dichroic mirror 67, an objective lens 51, an imaging lens 52, an imaging element 53, and the like. The dichroic mirror 67 transmits the anterior segment observation light and the alignment light. The imaging element 53 has an imaging surface arranged at a position conjugate with the anterior segment of the subject's eye E. The output from the imaging element 53 is input to the control unit 10. As a result, an anterior segment image of the subject's eye E is captured by the imaging element 53 and displayed on the monitor 6a. The observation optical system 50 also serves as an optical system for detecting alignment target images formed on the cornea of the subject's eye E by the first target projection optical system 30 and the second target projection optical system 40.

<Objective Measuring Optical System>
The objective measurement optical system is used as a part of the configuration of an objective measurement unit that objectively measures optical characteristics of the subject's eye E. As the optical characteristics of the subject's eye E, ocular refractive power, axial length, corneal shape, etc. may be measured. For example, the objective measurement optical system may be composed of a projection optical system and a light receiving optical system (for details, see, for example, JP 2018-47049 A).

<Internal structure>
Figures 3 to 5 are schematic diagrams of the inside of the subjective optometry device 100. Figure 3 is a diagram of the inside of the subjective optometry device 100 as viewed from the front. Figure 4 is a diagram of the inside of the subjective optometry device 100 as viewed from the side. Figure 5 is a diagram of the inside of the subjective optometry device 100 as viewed from above. For convenience, only the optical axis of the left eye measurement unit 7L is shown in Figures 4 and 5.

The subjective ophthalmology device 100 includes a subjective measurement unit. For example, the subjective measurement unit includes a measurement unit 7, a deflection mirror 91, a drive mechanism 92, a drive unit 93, a reflection mirror 94, a concave mirror 95, and the like. The subjective measurement unit is not limited to this configuration. For example, the subjective measurement unit may not include a reflection mirror 94. In this case, the visual target light beam from the measurement unit 7 may be irradiated from an oblique direction with respect to the optical axis L2 of the concave mirror 95 after passing through the deflection mirror 91. Also, for example, the subjective measurement unit may include a half mirror. In this case, the visual target light beam from the measurement unit 7 may be irradiated from an oblique direction with respect to the optical axis L of the concave mirror 95 via the half mirror, and the reflected light beam may be guided to the subject's eye E.

The subjective optometry device 100 has a left eye drive unit 96L and a right eye drive unit 96R, and can move the left eye measurement unit 7L and the right eye measurement unit 7R in the X direction. For example, by moving the left eye measurement unit 7L and the right eye measurement unit 7R, the distance between the measurement unit 7 and the deflection mirror 91 changes, and the presentation position in the Z direction of the visual target light beam from the measurement unit 7 is changed. As a result, the visual target light beam corrected by the correction optical system 70 is guided to the subject's eye E, and the measurement unit 7 is adjusted in the Z direction so that an image of the visual target light beam corrected by the correction optical system 70 is formed on the fundus of the subject's eye E.

For example, the deflection mirror 91 has a right-eye deflection mirror 91R and a left-eye deflection mirror 91L arranged in a pair on the left and right. For example, the deflection mirror 91 is arranged between the correction optical system 70 and the subject's eye E. That is, the correction optical system 70 in this embodiment has a left-eye corrective optical system and a right-eye corrective optical system arranged in a pair on the left and right, with the left-eye deflection mirror 91L arranged between the left-eye corrective optical system and the left eye EL, and the right-eye deflection mirror 91R arranged between the right-eye corrective optical system and the right eye ER. For example, the deflection mirror 91 is preferably arranged at a pupil conjugate position.

For example, the left eye deflection mirror 91L reflects the light beam projected from the left eye measurement unit 7L and guides it to the left eye EL. Also, for example, the left eye deflection mirror 91L reflects the fundus reflection light beam from the left eye EL and guides it to the left eye measurement unit 7L. For example, the right eye deflection mirror 91R reflects the light beam projected from the right eye measurement unit 7R and guides it to the right eye ER. Also, for example, the right eye deflection mirror 91R reflects the fundus reflection light beam from the right eye ER and guides it to the right eye measurement unit 7R. In this embodiment, a configuration using the deflection mirror 91 as a deflection member that reflects and guides the light beam projected from the measurement unit 7 to the subject eye E is described as an example, but is not limited to this. The deflection member may be, for example, a prism, a lens, etc., as long as it can reflect and guide the light beam projected from the measurement unit 7 to the subject eye E.

For example, the drive mechanism 92 is composed of a motor (drive unit) and the like. For example, the drive mechanism 92 has a drive mechanism 92L for driving the left-eye deflection mirror 91L and a drive mechanism 92R for driving the right-eye deflection mirror 91R. For example, the deflection mirror 91 rotates when driven by the drive mechanism 92. For example, the drive mechanism 92 rotates the deflection mirror 91 about a horizontal rotation axis (X direction) and a vertical rotation axis (Y direction). That is, the drive mechanism 92 rotates the deflection mirror 91 in the XY directions. Note that the rotation of the deflection mirror 91 may be either the horizontal direction or the vertical direction.

For example, the drive unit 93 is composed of a motor or the like. For example, the drive unit 93 has a drive unit 93L for driving the left eye deflection mirror 91L and a drive unit 93R for driving the right eye deflection mirror 91R. For example, the deflection mirror 91 moves in the X direction when driven by the drive unit 93. For example, by moving the left eye deflection mirror 91L and the right eye deflection mirror 91R, the distance between the left eye deflection mirror 91L and the right eye deflection mirror 91R is changed, and the distance in the X direction between the left eye optical path and the right eye optical path can be changed according to the interpupillary distance of the test eye E.

For example, multiple deflection mirrors 91 may be provided in each of the left eye optical path and the right eye optical path. For example, two deflection mirrors may be provided in each of the left eye optical path and the right eye optical path (for example, two deflection mirrors may be provided in the left eye optical path, etc.). In this case, one deflection mirror may be rotated in the X direction, and the other deflection mirror may be rotated in the Y direction. For example, by rotating and moving the deflection mirror 91, the apparent light beam for forming an image of the visual target light beam in front of the subject's eye can be deflected, and the position where the image of the visual target light beam is formed can be optically corrected.

For example, the concave mirror 95 is shared by the left eye measurement unit 7L and the right eye measurement unit 7R. For example, the concave mirror 95 is shared by the left eye optical path including the left eye correction optical system and the right eye optical path including the right eye correction optical system. That is, the concave mirror 95 is arranged at a position where it passes through both the left eye optical path including the left eye correction optical system and the right eye optical path including the right eye correction optical system. Of course, the concave mirror 95 does not have to be configured to be shared by the left eye optical path and the right eye optical path. That is, a concave mirror may be provided in each of the left eye optical path including the left eye correction optical system and the right eye optical path including the right eye correction optical system. For example, the concave mirror 95 guides the visual target light beam that has passed through the correction optical system 70 to the subject's eye E, and forms an image of the visual target light beam that has passed through the correction optical system 70 in front of the subject's eye E.

<Optical path of subjective measurement unit>
The optical path of the subjective measurement unit will be described by taking the optical path for the left eye as an example. The optical path for the right eye has the same configuration as the optical path for the left eye. For example, in the subjective measurement unit for the left eye, the visual target light beam emitted from the display 61 in the subjective measurement optical system 20 enters the astigmatism correction optical system 80 through the projection lens 62, and when it passes through the astigmatism correction optical system 80, it is guided from the left eye measurement unit 7L to the left eye deflection mirror 91L via the projection lens 63, the reflection mirror 64, the objective lens 65, the dichroic mirror 66, and the dichroic mirror 67. The visual target light beam reflected by the left eye deflection mirror 91L is reflected by the reflection mirror 94 toward the concave mirror 95. The visual target light beam emitted from the display 61 passes through each optical member in this way and reaches the left eye EL through the presentation window 3.

As a result, an image of the visual target light beam corrected by the correction optical system 70 is formed on the fundus of the left eye EL, based on the eyeglass wearing position of the left eye EL (for example, about 12 mm from the corneal apex position). Therefore, adjustment of the spherical power by the spherical power correction optical system (in this embodiment, driving the drive mechanism 75) is performed in front of the eye, which is equivalent to placing the astigmatism correction optical system 80 in front of the eye. The subject can collimate the image of the visual target light beam optically formed in front of the eye at a predetermined test distance optically via the concave mirror 95 in a natural state.

<Control Unit>
6 is a diagram showing a control system of the subjective ophthalmology device 100. For example, the control unit 10 is electrically connected to various components such as the monitor 6a, the non-volatile memory 15 (hereinafter, memory 15), the display 61 of the measurement unit 7, the image sensor 53, etc. In addition, for example, the control unit 10 is electrically connected to driving units (not shown) provided in the driving mechanism 75, the driving unit 93, the driving unit 96, etc.

For example, the control unit 10 includes a CPU (processor), a RAM, a ROM, etc. For example, the CPU controls each component in the subjective optometry device 100. For example, the RAM temporarily stores various information. For example, the ROM stores various programs, optotypes, initial values, etc. for controlling the operation of the subjective optometry device 100. Note that the control unit 10 may be composed of multiple control units (i.e., multiple processors).

For example, memory 15 is a non-transient storage medium that can retain its contents even if the power supply is cut off. For example, memory 15 can be a hard disk drive, a flash ROM, a USB memory, etc.

<Control operation>
The control operation of the subjective optometry apparatus 100 will be described.

In subjective measurements using subjective eye examination devices, the subject is asked whether he or she can confirm the test target, and the test target presented to the subject's eye and the correction power used to correct the subject's eye are changed depending on whether the subject answers correctly. For example, the subject is asked whether he or she can read the direction of the slits in a Landolt ring target, and the test target and correction power are changed depending on whether the reading is correct. However, even if the subject is not gazing at the Landolt ring target, there is a certain probability that the answer will be correct if the subject answers by intuition. It is difficult for the examiner to determine whether an answer is correct based on intuition, and such correct answers may be mixed in, so there is a possibility that correct measurement results may not be obtained with conventional measurements.

Therefore, in the subjective measurement in this embodiment, not only the subject's answers but also the gaze information of the test eye is used to obtain measurement results that take into account correct answers based on intuition. In particular, measurement results are obtained that take into account cases where the test eye gives a correct answer even though the test eye is not looking at the test target. This makes it possible to improve the measurement accuracy of the test eye E.

Details are explained below.

<Alignment of the test eye and the measurement unit>
The examiner places the subject's face against the forehead rest 4 and chin rest 5, and has the subject's eye E fixate on a fixation target displayed on the display 61. The control unit 10 projects an alignment index onto the cornea of the subject's eye E and photographs the anterior segment to obtain an anterior segment image including an alignment index image (a bright spot image described below). The control unit 10 also detects the amount of deviation of the measurement unit 7 from the subject's eye E in the X, Y, and Z directions, based on the alignment index image, and moves the measurement unit 7 based on the amount of deviation. This automatically aligns the subject's eye E with the measurement unit 7.

<Subjective measurement>
Next, the examiner performs a subjective measurement of the subject's eye E. In this embodiment, answer information on the interpretation result of the subject interpreting the test optotype and line-of-sight information on the subject's line of sight are acquired, and a change control described later is performed based on these pieces of information.

<Acquisition of response information>
First, the acquisition of the subject's answer information will be described. For example, the Landolt ring is presented to the subject through the presentation window 3, and the subject is asked to indicate the direction of the slit. The subject reads the direction of the slit of the Landolt ring and tilts the answer lever 8a or presses the answer button 8b. The control unit 10 detects whether the subject's answer is correct or incorrect based on the direction of the slit of the Landolt ring presented to the subject's eye and the signal from the answer lever 8a or the answer button 8b, and acquires the detection result as answer information.

For example, if a signal is input from the answer lever 8a, the subject's answer is detected as correct or incorrect. As an example, if the direction of the slit in the Landolt ring and the tilt direction of the answer lever 8a match, the answer is detected as correct, and if they do not match, the answer is detected as incorrect. Also, for example, if a signal is input from the answer button 8b, the subject's answer is detected as no answer (don't know).

<Acquisition of gaze information>
Next, acquisition of the subject's line of sight information will be described. Fig. 7 is an example of an anterior eye image 200 of the subject's eye E. The anterior eye image 200 includes a bright spot image R that appears due to the infrared light sources of the first target projection optical system 30 and the second target projection optical system 40. For example, the bright spot image R may be composed of a ring target image R1 that appears due to the infrared light source of the first target projection optical system 30 and a ring target image R2 that appears due to the infrared light source of the second target projection optical system 40.

The control unit 10 performs image processing on the anterior eye image 200 to detect the pupil and the bright spot image R. For example, the pupil may be detected using the luminance information of the anterior eye image 200, and the center of the pupil may be calculated to detect the pupil center P. For example, the luminance information of the anterior eye image 200 may be used to detect the bright spot image R, and the corneal apex K may be detected by calculating the center of either the ring index image R1 or the ring index image R2. Furthermore, the control unit 10 detects the direction of the corneal apex K relative to the pupil center P and the amount of deviation Δd, and specifies the direction of the line of sight of the subject eye E. For example, the amount of deviation Δd may be calculated by calculating the number of pixels between the pixel position of the pupil center P and the pixel position of the corneal apex K. Note that the greater the line of sight of the subject eye E moves and the greater the eye position of the subject eye E (for example, the angle of rotation relative to the optical axis L1 based on the center of rotation of the subject eye), the greater the amount of deviation Δd. The direction of the line of sight of the subject's eye E is appropriately determined by calculating the deviation amount Δd. The control unit 10 can detect the line of sight position V (see FIG. 10 ) at which the subject's eye E gazes at the Landolt ring target based on the direction of the line of sight of the subject's eye E and the distance from the subject's eye E to the display 61 (i.e., the examination distance).

FIG. 8 is an example of the display 61. The Landolt ring T is provided with a detection area D1 for detecting whether the position of the line of sight coincides with the Landolt ring T. For example, the detection area D1 may be provided for the entire Landolt ring T, or may be provided for a portion of it (for example, a slit portion). Also, for example, the detection area D1 may be provided as a fixed area (i.e., a fixed size and shape) in which the entire or a portion of the Landolt ring T is viewed. Note that, for example, the size and shape of the detection area D1 may be manually set by the examiner, or may be automatically set based on the results of an experiment or simulation. In this embodiment, the detection area D1 is automatically set for the entire Landolt ring T.

The control unit 10 acquires, as gaze information, a judgment result of whether or not the subject eye is gazing at the Landolt ring target T based on the direction of the gaze of the subject eye. For example, based on a detection result of detecting whether or not the gaze position V of the subject eye E obtained by analyzing the anterior eye image 200 of the subject eye E as described above is included in the detection area D1 set for each Landolt ring target, a judgment result of whether or not the subject eye is gazing at the Landolt ring target T is acquired.

As an example, the control unit 10 may determine that the subject eye E is gazing at the Landolt ring target T when it detects that the gaze position V of the subject eye E is included in the detection area D1 for a predetermined time or more (for example, for one second or more). Also, when it detects that the gaze position V of the subject eye E is included in the detection area D1 for less than a predetermined time or is not included in the detection area D1, it may determine that the subject eye E is not gazing at the Landolt ring target T.

When detecting whether or not the gaze position V is included in the detection area D1, the timing at which a signal is input from the answer lever 8a or the answer button 8b may be taken into consideration. For example, it may be considered whether the answer lever 8a or the answer button 8b is operated when the gaze position V is included in the detection area D1. Of course, it may also be considered, for example, whether or not the gaze position V was included in the detection area D1 during the time between the time when the answer lever 8a or the answer button 8b is operated and the time a predetermined time before this time (as an example, the time one second before).

Figure 9 is a flow chart showing an example of the flow of subjective measurement. For example, subjective measurement is performed in the order of adjusting the correction power of the test eye E (step A), obtaining the best visual acuity value of the test eye E (step B), and obtaining whether or not the test eye E is adjusted (step C). Based on these results, the subjective value of the test eye E is obtained (step D). The subjective value of the test eye may be the fully corrected value of the test eye or the prescription value. The fully corrected value is the most positive correction power value that provides the best visual acuity of the test eye. The prescription value is a value used when prescribing glasses, and is a correction power value that provides a specified visual acuity.

Below, steps A, B, C, and D will be explained in order, using the example of obtaining a perfect correction value as the subjective value of the examined eye.

<Adjustment of correction power (Step A)>
The examiner operates the monitor 6a to start the subjective measurement. The control unit 10 sets the correction power for correcting the test eye E to a predetermined ocular refractive power based on the objective value of the test eye E acquired in advance in response to a signal from the monitor 6a. For example, the control unit 10 controls at least one of the correction optical system 70 and the projection optical system 60 based on the set correction power. As an example, the display 61 may be moved in the direction of the optical axis L1 to correct the spherical power of the test eye E. As another example, the control unit 10 may rotate the cylindrical lenses 81a and 81b around the optical axis L1 to correct at least one of the cylindrical power and the astigmatism axis angle of the test eye E. For example, the test eye E is corrected to 0D.

The control unit 10 performs multiple tests on the subject's eye E to adjust the correction power of the subject's eye E as appropriate. For example, first, a red-green optotype is displayed on the display 61 to perform a red-green test on the subject's eye E. The subject answers whether the red optotype or the green optotype was clearly visible. The control unit 10 changes the spherical power based on the subject's answer. For example, next, a point cloud optotype is displayed on the display 61 to perform a cross cylinder test on the subject's eye E. The subject answers whether the two point cloud optotypes were clearly visible. The control unit 10 changes the astigmatism axis angle and cylinder power based on the subject's answer.

The control unit 10 may acquire gaze information of the subject's eye E (whether the subject's eye E is gazing at each target) as described below. In this case, the gaze information of the subject's eye E may be used together with the subject's response information (answers by the subject) to appropriately change the correction power of the subject's eye E. For example, this allows the correction power of the subject's eye E to be appropriately adjusted.

<Obtaining the highest visual acuity value (Step B)>
10 is a flowchart showing an example of change control in obtaining the highest visual acuity value. The control unit 10 sets the state of presentation of the test optotype to the subject's eye E to the initial state. For example, the control unit 10 corrects the subject's eye E with the correction power adjusted in step A (step B1), and displays a predetermined test optotype on the display 61 (step B2). As an example, a Landolt ring with a slit facing rightward and a visual acuity value of 1.0 is displayed as the predetermined test optotype.

For example, the display 61 is provided with a presentation area J for presenting the test optotype (in other words, a display area J for displaying the test optotype). As an example, the presentation area J is provided based on the center of the display 61, and the test optotype is displayed based on the center of the presentation area J. This allows the subject's eye E to visually recognize a predetermined Landolt ring optotype.

When the presentation state of the test target for the subject's eye is set to the initial state, a voice guide is generated from a speaker or the like (not shown) and the direction of the slit of the Landolt ring target is asked. At this time, the control unit 10 changes the presentation state of the Landolt ring target for the subject's eye based on the answer information of the subject (whether the answer by the subject is correct or incorrect) and the gaze information of the subject's eye (whether the subject is gazing at the Landolt ring target T). For example, the presentation state is changed from the initial state (in other words, the first state) in which the corrective power adjusted in step A is given and a Landolt ring target with a visual acuity value of 1.0 and a slit facing to the right is presented, to a second state in which at least one of the corrective power or the Landolt ring target is different. Note that the state in which the corrective power is different may be a state in which at least one of the spherical power, the cylindrical power, and the astigmatism axis angle is different. Furthermore, a state in which the Landolt ring is different may be a state in which at least one of the direction of the slits in the Landolt ring and the visual acuity value is different.

The control unit 10 determines whether the subject's eye E is gazing at the visual target in the initial state of the subject's eye E (step B3), and when it detects whether the subject's answer is correct or incorrect (step B4), it changes the initial state to the second state based on these results.

The control unit 10 first considers the result of the judgment of whether the subject's eye E is gazing at the optotype, thereby eliminating the possibility that the subject answered the direction of the slit without looking at the Landolt ring. For example, if the judgment result indicates that the subject's eye E is not gazing at the optotype (step B3: NO), the visual acuity value of the Landolt ring may be changed to a lower visual acuity value regardless of whether the subject's answer is correct or incorrect. As an example, the visual acuity value of the Landolt ring may be changed to a visual acuity value one level lower (i.e., the visual acuity value of the Landolt ring may be changed from 1.0 to 0.9). Also, for example, the direction of the slit of the Landolt ring may be changed regardless of whether the subject's answer is correct or incorrect. As an example, the direction of the slit of the Landolt ring may be changed from right to left. Of course, the visual acuity value of the Landolt ring may be lowered and the direction of the slit may be changed.

This sets a second state in which at least either the visual acuity value or the direction of the slits of the Landolt ring is different from the initial state (step B5). This also prevents the measurement results from reflecting correct answers given without looking at the Landolt ring. After this, the process may return to step B3 in the second state, and control may be performed based on the flowchart.

For example, if the determination result indicates that the subject's eye E is gazing at the target (step B3: YES), the system determines whether the subject is viewing the Landolt ring target by taking into consideration the detection result that detects whether the subject's answer is correct or incorrect.

For example, if the detection result indicates that the subject's answer is incorrect or that there is no answer (step B4: NO), the visual acuity value of the Landolt ring is changed to a lower value. At this time, the direction of the slits in the Landolt ring may be changed along with the visual acuity value of the Landolt ring. This sets a second state in which at least the visual acuity value of the Landolt ring is lower than the initial state (step B6).

For example, if the detection result indicates that the subject's answer is correct (step B4: YES), the visual acuity value of the Landolt ring is changed to be higher. As an example, the visual acuity value of the Landolt ring is changed to a visual acuity value one level higher (i.e., the visual acuity value of the Landolt ring is changed from 1.0 to 1.2). At this time, the direction of the slits in the Landolt ring may be changed along with the visual acuity value of the Landolt ring. This sets a second state in which the visual acuity value of at least the Landolt ring is higher than the initial state (step B10).

When the presentation state of the Landolt ring target for the subject's eye E is changed to each of the second states, the direction of the gap in the Landolt ring target is again queried. As in steps B3 and B4, the control unit 10 performs change control based on the determination result of whether the subject's eye E is gazing at the target and the detection result of whether the subject's answer is correct or incorrect (steps B7 to B9, and steps B11 to B13).

When proceeding to step B6 with the second state set, if the subject's eye E gazes at the target and the answer is correct, the highest visual acuity value in the state in which the subject's eye E is corrected with the correction power adjusted in step A is obtained (step B14). For example, the visual acuity value of the Landolt ring target presented to the subject's eye E in the second state (i.e., the Landolt ring target for which the answer was correct) is obtained as the highest visual acuity value.

In addition, when proceeding to step B10 with the second state set, if the subject's eye E gazes at the optotype and the answer is incorrect or no answer, the highest visual acuity value in the state in which the subject's eye E is corrected with the correction power adjusted in step A is obtained (step B14). For example, the highest visual acuity value obtained is not the visual acuity value of the Landolt ring optotype presented to the subject's eye E in the second state, but the visual acuity value of the Landolt ring optotype presented to the subject's eye E in the previous state (here, the initial state) and answered correctly.

When proceeding to step B6 with the second state set, if the subject's eye E gazes at the Landolt ring and the answer is incorrect, the process may return to step B6 and set the third state in which the visual acuity value of the Landolt ring is low. When proceeding to step B10 with the second state set, if the subject's eye E gazes at the Landolt ring and the answer is correct, the process may return to step B10 and set the third state in which the visual acuity value of the Landolt ring is high.

Regardless of whether the second state is set by proceeding to step B6 or step B10, if the line of sight does not match the Landolt target, the same change control as step B5 is performed, and a third state may be set in which at least either the visual acuity value or the direction of the slits of the Landolt target is different (steps B9 and B13).

The control unit 10 changes the presentation state of the Landolt ring target for the subject's eye E from the initial state to each of the second state, the third state, ..., the nth state in accordance with the flowchart. For example, the control unit 10 repeats such control and sequentially changes the presentation state to obtain the highest visual acuity value when the subject's eye E is corrected with the correction power adjusted in step A.

<Obtaining Adjustment (Step C)>
11 is a flow chart showing an example of change control in acquiring the presence or absence of adjustment. The control unit 10 corrects the eye E with the correction power adjusted in step A (step C1), and displays the Landolt ring on the display 61 (step C2). For example, the state in which the highest visual acuity value of the eye E is acquired in step B is reproduced. Note that, since the correction power is not changed from the initial state in step B, when moving from step B to step C, only the Landolt ring needs to be changed.

Then, the control unit 10 changes the correction power of the test eye E from the initial state (the state where the highest visual acuity value is obtained) to a lower value (step C3). As an example, the spherical power is changed to a power one step lower (i.e., the spherical power is increased by +0.25 D). Of course, it is not limited to the spherical power, and the cylindrical power or the astigmatism axis angle may also be changed.

Here, the subject is asked to indicate the direction of the gap in the Landolt ring target. The control unit 10 performs change control based on the determination result of whether the subject's eye E is gazing at the target or not and the detection result of whether the subject's answer is correct or incorrect (steps C4 to C6). Note that the details of these steps are omitted as they are the same as those in step B.

For example, if the subject's eye E is gazing at the target and the answer is correct, it is determined that accommodation is working (step C7). In this case, the process may return to step B6, where the correction power is set to a level one step lower, and control may be performed based on the flowchart.

For example, if the subject's eye E gazes at the target and the answer is incorrect or there is no answer, it is determined that accommodation is not working (step C8). The control unit 10 repeatedly changes the correction power of the subject's eye E in accordance with the flowchart until it is determined that accommodation is not working in the subject's eye E.

<Acquisition of perfect correction value>
The control unit 10 adjusts the subject's eye E to a predetermined correction power in step A, obtains the highest visual acuity value in a state in which the subject's eye E is corrected with the predetermined correction power in step B, and further reduces the correction power until the adjustment of the subject's eye E no longer works in step C, thereby obtaining the weakest correction power at which the subject's eye E has the highest visual acuity as the fully corrected value of the subject's eye E. The control unit 10 also stores the fully corrected value of the subject's eye E in the memory 15.

<Correction of optical aberration components>
In the subjective measurement of the eye E, a third optical aberration component is generated based on the first optical aberration component generated by the subjective measurement unit and the second optical aberration component generated by the optical characteristics (eye refractive power) of the eye E. For example, the first optical aberration component is generated because the reflection position or reflection area (i.e., the beam diameter of the visual target beam) of the visual target beam on the concave mirror 95 changes due to at least one of the alignment state of the eye E, the correction power (i.e., spherical power, cylindrical power, astigmatism axis angle, etc.) set in the correction optical system 70, the convergence angle of the visual target beam, etc. For example, the second optical aberration component is generated because the shape of the visual target beam changes due to at least one of the spherical power, cylindrical power, and astigmatism axis angle of the eye E. For example, the third optical aberration component is a composite optical aberration component in which the first optical aberration component and the second optical aberration component are combined. For details about these optical aberration components, see, for example, JP-A-2019-118551.

Therefore, the control unit 10 may obtain the third optical aberration component and correct it. For example, the third optical aberration component may be obtained using a table or an arithmetic formula created in advance based on the results of experiments or simulations, and such aberration may be corrected by changing the correction power based on the third optical aberration component. In addition, for example, a simulation may be appropriately performed to track the visual target light beam when the correction power is changed in a calculation, a value of the correction power that removes the third optical aberration component may be found, and the correction power may be changed accordingly to correct such aberration (i.e., optimization may be performed). In this case, a simulation may be performed based on the positional relationship between the display 61 and the correction optical system 80, which is known by design. The control unit 10 may more accurately obtain the subjective value of the test eye by reducing the influence of the third optical aberration component.

Second Example
The above explanation uses a subjective eye examination device as an example, but with a visual acuity testing device, the presentation state of the Landolt ring target to the test eye E can also be appropriately changed based on the subject's response information and the gaze information of the test eye E, thereby making it possible to appropriately measure visual acuity.

Figure 12 is an external view of the vision testing device 300. The vision testing device 300 includes a housing 301, a presentation window 302, a subject controller 303, a speaker 305, a printer 306, a lamp 307, a control box 308, etc.

The housing 301 has an optical system inside, which will be described later. The housing 301 also has a presentation window 302, a subject controller 303, an anterior eye illumination lamp 304, a speaker 305, etc., on the front side. The housing 301 also has a printer 306, a lamp 307, a control box 308, etc., on the side.

The presentation window 302 presents a test optotype from inside the housing 301 to the outside. The presentation window 302 has a presentation window 302L for the left eye and a presentation window 302R for the right eye. For example, the subject can look into the presentation window 302 (presentation window 302L for the left eye and presentation window 302R for the right eye) to see the test optotype presented in the optotype window 314 (see Figures 13 and 14) and have their visual acuity measured.

The subject controller 303 includes an input button 303a03a, a response button 303b, a response lever 303c, etc. The input button 303a is used by the subject when starting the visual acuity test. The response button 303b is used by the subject when he/she is unable to interpret the presented test optotype. The response lever 303c is used by the subject when inputting the result of interpreting the presented test optotype.

The anterior eye illumination lamp 304 emits near-infrared light for illuminating the subject's eye E, thereby illuminating the subject's eye E. The anterior eye illumination lamp 304 has an anterior eye illumination lamp 304L for the left eye and an anterior eye illumination lamp 304R for the right eye. The anterior eye illumination lamp 304 may be configured to be shared by both the left and right eyes. The anterior eye illumination lamp 304 is disposed at a position where it can illuminate the subject's eye E. In this embodiment, it is disposed around the presentation window 302. Of course, it may also be disposed, for example, in a depression 309 where the subject's nose is located. Also, for example, in the anterior eye observation unit 330 described below, the light path between the image sensor 333 and the image pickup lens 332 may be branched by a beam splitter or the like.

The speaker 305 outputs audio guidance and the like. The speaker 305 may be configured with one on each side, or one shared by both the left and right. The printer 306 outputs the test results. The lamp 307 notifies the examiner of the test status and test results, etc. The lamp 307 is placed in a position that is not visible when the examinee looks into the presentation window 302. The lamp 307 is equipped with multiple LEDs (light-emitting diodes) and is capable of emitting light in multiple colors (for example, two colors, green and orange). Of course, the lamp 307 may be configured to be composed of a single LED and emit light in a single color.

The control box 308 includes a monitor 308a. The monitor 308a functions as a touch panel that combines an operation unit for the examiner to input parameters, etc., and a display unit for checking the input parameters, etc. Signals from the control box 308 are output to the control unit 340 via a cable 310. The control box 308 may be configured to be integral with the housing 301.

<Optical system>
Fig. 13 is a schematic diagram of the right-eye optical system when the vision testing device 300 is viewed from the right side. The left-eye optical system when the vision testing device 300 is viewed from the left side has the same configuration as the right-eye optical system, so a description thereof will be omitted. Fig. 14 is a schematic diagram of the right-eye optical system and the left-eye optical system of the vision testing device 300 when viewed from above. Note that Fig. 14 also illustrates the configuration of the control system.

For example, the interior of the housing 301 includes eyepieces 311L and 311R, internal covers 312L and 312R, internal illumination lamps 313L and 313R, target windows 314L and 314R, a target presentation section 320, an anterior eye observation section 330, etc.

The eyepieces 311L and 311R are disposed in the left eye presentation window 302L and the right eye presentation window 302R, respectively. As a result, when a test optotype is placed in the optotype window 314 provided on the rear side of the presentation window 302 (left eye presentation window 302L and right eye presentation window 302R), the test optotype appears to be presented at an apparent distance (e.g., 5 m) away to the subject's eye E.

The internal lighting lamps 313L and 313R illuminate the visual field space created by the internal covers 312L and 312R. The internal covers 312L and 312R are cylindrical covers with a partition plate in the center. This ensures separate visual fields for the left eye EL and the right eye ER to view the test target, and allows the left and right optical paths to be separated.

For example, in this embodiment, the inner covers 312L and 312R have the same shape. Also, for example, the inner covers 312L and 312R have left and right inner wall surfaces formed symmetrically around the optical axis M1L emitted from the target illumination lamp 323L described later and passing through the eyepiece lens 311L, and the optical axis M1R emitted from the target illumination lamp 323R and passing through the eyepiece lens 311R. Also, for example, the rear surfaces of the inner covers 312L and 312R are provided with target windows 314L and 314R, respectively. Therefore, when both test eyes (i.e., both eyes of the left test eye EL and the right test eye ER) look into the presentation window 302, the target window 314L and the target window 314R are fused and seen as one, and the left and right inner wall surfaces of the inner covers 312L and 312R are observed as one visual field space. For example, this allows the subject to comfortably view a test target placed at an apparent distance.

The inner surfaces of the internal covers 312L and 312R are painted in a matte white color, and during normal vision tests and during light adaptation for measuring vision recovery time, both are illuminated to a predetermined brightness by the internal illumination lamps 313L and 313R. The internal illumination lamps 313L and 313R are positioned so that their illumination light does not directly strike the subject's eye.

The optotype presenting unit 320 is used to switch and place the test optotypes in the optotype window 314. For example, the optotype presenting unit 320 includes an optotype plate 321, a motor 322, and optotype illumination lamps 323L and 323R. The optotype plate 321 is made of a light-transmitting glass plate. On this glass plate, a test optotype with a direction (for example, a Landolt ring optotype with a direction in the up, down, left, right, etc.) is formed by a light-shielding chrome coating. For example, such a test optotype may be formed in 12 stages of visual acuity values 0.1 to 1.0, 1.2, and 1.5. Also, for example, such a test optotype may be formed to correspond to the positions of the optotype windows 314L and 314R so that the same paired test optotypes for the left eye EL and the right eye ER can be simultaneously presented.

The motor 322 rotates the optotype plate 321. As a result, the test optotypes for the left eye and the right eye are placed in the optotype windows 314L and 314R, respectively. The optotype illumination lamps 323L and 323R illuminate the optotype plate 321 from behind. As a result, the test optotypes placed in the optotype windows 314L and 314R are presented toward the presentation windows 302L and 302R.

In this embodiment, a display may be used as the optotype presenting unit 320, and the test optotype may be switched and positioned by controlling the display of the display. For example, in this case, a display may be provided on the inner back surface of the inner covers 312L and 312R.

The anterior eye observation unit 330 is used to observe the anterior eye of the subject's eye E. The anterior eye observation unit 330 includes a beam splitter 331, an imaging lens 332, an imaging element 333, and the like. The beam splitter 331 transmits the target light beam emitted by the target illumination lamps 323L and 323R when they illuminate the test target. The beam splitter 331 also reflects the light beam reflected by the anterior eye illumination lamps 304L and 304R at the anterior eye. The imaging element 333 has an imaging surface arranged at a position conjugate with the anterior eye of the subject's eye E. The output from the imaging element 333 is input to the control unit 340. As a result, an image of the anterior eye of the subject's eye E is captured and acquired by the imaging element 333.

For example, the anterior eye observation section 330 may be provided in a pair on the left and right sides, each having an anterior eye observation section for the left eye and an anterior eye observation section for the right eye. Of course, for example, the anterior eye observation section 330 may be provided so that at least a portion of the anterior eye observation section for the left eye and the anterior eye observation section for the right eye are shared. As an example, only the image sensor 333 may be shared. As another example, the beam splitter 331, the image sensor 332, and the image sensor 333 may all be shared. In this case, part of the partition plate in the center of the inner cover 312 may be removed and the beam splitter 331 may be placed therein.

<Control system>
For example, the control unit 340 supervises and controls each unit of the vision testing device 300. For example, the control unit 340 may be configured to include a CPU (processor), RAM, ROM, etc. For example, the CPU controls the driving of each component in the vision testing device 300. For example, the RAM temporarily stores various information. For example, the ROM stores programs to be executed by the CPU. Note that the control unit 340 may be configured by multiple control units (i.e., multiple processors).

For example, the control unit 340 is electrically connected to an input button 303a, a response button 303b, a response lever 303c, a speaker 305, a printer 306, a lamp 307, anterior segment illumination lamps 304L and 304R, internal illumination lamps 313L and 313R, a motor 322, target illumination lamps 323L and 323R, a non-volatile memory 345 (memory 345), a control box 308, and the like.

For example, memory 345 is a non-transient storage medium that can retain its contents even if the power supply is cut off. For example, memory 345 may be a hard disk drive, a flash ROM, a USB memory, etc.

<Control operation>
The control operation of the visual acuity testing apparatus 300 will now be described.

The examiner has the subject look into the presentation window 302. The control unit 340 detects that the subject is approaching using a proximity sensor (not shown).

For example, at this time, the speaker 305 issues a voice guide stating, "Your visual acuity will be measured automatically. Please lightly push the lever." In response to a signal indicating that the response lever 303c has been pushed, the control unit 340 turns on the anterior eye illumination lamp 304 (anterior eye illumination lamps 304L and 304R), the internal illumination lamp 17 (internal illumination lamps 313L and 313R), and the target illumination lamp 323 (target illumination lamps 323L and 323R).

For example, the speaker 305 then issues a voice guide stating, "Your visual acuity will be measured. Lightly tilt the lever in the direction of the broken loop. If you are unsure of the direction of the broken loop, press the button in front." When the subject responds using the response lever 303c or response button 303b, a visual acuity test program for determining the visual acuity of the subject's eye is executed. Note that, for example, in such a visual acuity test program, the highest visual acuity value of the subject's eye E without eye contact is obtained.

Figure 15 is a flow chart showing an example of change control in the visual acuity testing device 300. For example, the control unit 340 sets the presentation state of the test optotype for the subject's eye E to the initial state. As an example, the control unit 340 rotates the optotype plate 321 and places a Landolt ring optotype with a visual acuity value of 0.5 as an initial test optotype in the optotype window 314 (optotype windows 314L and 314R) (step N1). Next, for example, the control unit 10 generates a voice guide such as "direction" from the speaker 305. The subject gazes at the Landolt ring optotype, determines the direction of the slit in the Landolt ring optotype, and tilts the response lever 303c in that direction or presses the response button 303b.

Here, the control unit 340 uses the anterior eye image photographed and acquired by the anterior eye observation unit 330 to determine whether the subject's eye E is gazing at the Landolt ring target T, as in the first embodiment (step N2). The control unit 340 also detects whether the subject's answer is correct or incorrect, as in the first embodiment, based on the direction of the slit in the Landolt ring target presented to the subject's eye and the signal from the response lever 303c or the response button 303b (step N3). Furthermore, the control unit 340 changes the presentation state of the Landolt ring target to the subject's eye from the initial state to the second state based on the judgment result obtained in step N2 (i.e., the line of sight information of the subject's eye E) and the detection result obtained in step S3 (i.e., the subject's answer information).

Note that steps N2 to N13 in FIG. 15 are basically the same as steps B3 to B14 in FIG. 10, and therefore will not be described in detail. The control unit 10 changes the presentation state of the Landolt ring target for the subject's eye E from the initial state to each of the second state, the third state, ..., the nth state in accordance with the flowchart. For example, the control unit 10 repeats this control and appropriately changes at least one of the visual acuity value and the direction of the slits of the Landolt ring target presented in the target window 314 to a different state, thereby obtaining the highest visual acuity value for the subject's eye E with the naked eye.

As explained above, for example, the eye examination device in this embodiment acquires answer information regarding the subject's interpretation of the test optotype and gaze information regarding the gaze of the subject's eye, and changes the presentation state of the test optotype to the subject's eye based on the answer information and gaze information. This makes it possible to obtain accurate test results that take into account the position and direction of the gaze of the subject's eye as well as the correctness of the subject's answer.

In addition, for example, the eye examination device in this embodiment obtains a judgment result of whether or not the subject's eye is gazing at the test target as gaze information related to the gaze of the subject's eye. This makes it easy to distinguish whether the subject's answer was given while looking at the test target or without looking at the test target, and allows for accurate test results to be obtained.

In addition, for example, the eye examination device in this embodiment is provided with a detection area for each examination area to detect whether the position of the gaze of the subject's eye coincides with the position of the test target, and a judgment result is obtained that judges whether the subject's eye is gazing at the test target based on whether the position of the gaze is included in the detection area. This clarifies the judgment criteria for gazing at the test target, and makes it easy to obtain a judgment result.

In addition, for example, when the eye examination device in this embodiment receives an input signal containing the result of the subject's interpretation of the test optotype, it obtains a judgment result that judges whether or not the subject's eye is gazing at the test optotype based on whether or not the position of the gaze is included in the detection area. This allows for cases where the gaze happens to meet the test optotype, and makes it possible to obtain a judgment result with high accuracy.

For example, the eye examination device in this embodiment is equipped with a correction means for changing the optical characteristics of the visual target light beam in order to change the correction power for correcting the eye to be examined, and the state in which the test visual target is presented to the eye to be examined is changed to a presentation state with a different correction power by controlling the correction means. As an example, at least one of the spherical power, cylindrical power, astigmatism axis angle, etc. is changed to a different state before and after the change. This allows the correction power to be appropriately adjusted based on the response information and line of sight information, improving the accuracy of the examination.

<Example of transformation>
In this embodiment, the presenting position of the Landolt ring is the center of the display 61 or the target window 314, but the presenting position is not limited to this. For example, the presenting position of the Landolt ring does not necessarily have to be a fixed position, and may be a random position.

When the Landolt ring is placed at random positions in the subjective optometry device 100, the display 61 may be provided with multiple display areas. For example, the display surface of the display 61 may be divided into any number of vertical and horizontal sections to provide multiple display areas. As an example, in this embodiment, the display surface of the display 61 is divided into 3 x 3 sections (divided into three vertically and three horizontally). Of course, some of the multiple display areas may overlap, or a different layout may be used.

For example, in change control according to the flowchart of FIG. 10, the control unit 10 randomly selects one of the multiple display areas. The control unit 10 also displays a Landolt ring with a different visual acuity value or a different slit direction in the center of the selected display area. For example, in this way, the Landolt ring can be positioned in a random position.

When the Landolt ring targets are arranged at random positions in the visual acuity testing device 300, the target window 314 in the target presentation unit 320 may be made large and multiple Landolt ring targets may be arranged in the target window 314. Also, a mask plate for masking the Landolt ring target may be rotatably arranged in front of the target plate 321. For example, the target plate 321 and the mask plate are controlled independently.

For example, in the change control according to the flowchart of FIG. 15, the control unit 340 rotates the target plate 321 to present multiple Landolt ring targets, including Landolt ring targets with different visual acuity values or slit directions. The control unit 340 also rotates the mask plate to mask the remaining Landolt ring targets, excluding the target Landolt ring target. For example, in this way, the Landolt ring targets can be arranged in random positions.

For example, the eye examination device in this embodiment includes an optotype presenting means for presenting a test optotype to the eye to be examined by emitting an optotype light beam toward the eye to be examined, and the presentation state of the test optotype to the eye to be examined is changed to a presentation state in which the test optotypes are different from each other by controlling the optotype presenting means. As an example, in the case of a test optotype that has directionality such as a Landolt ring optotype, at least one of the orientation of the test optotype, the visual acuity value of the test optotype, etc. is changed to a different state before and after the change. As a result, the test optotype is appropriately put into an appropriate state based on the response information and line of sight information, thereby improving the accuracy of the examination.

In this embodiment, the case where the bright spot image R projected onto the subject's eye E is used to obtain the gaze information of the subject's eye E has been described as an example, but the present invention is not limited to this. For example, the gaze movement of the subject's eye E may be obtained in advance, and the gaze information of the subject's eye E may be obtained based on this. In this case, before starting the subjective measurement or visual acuity test, the control unit presents a fixation target to the subject's eye E, and obtains a first detection result that detects the gaze position, pupil position, eye movement, etc., of the subject's eye E gazing at the fixation target. After starting the subjective measurement or visual acuity test, the control unit obtains a second detection result that detects the gaze position, pupil position, eye movement, etc., of the subject's eye E gazing at the Landolt ring target (test target). For example, the control unit can obtain a judgment result that judges whether the subject's eye is gazing at the Landolt ring target by comparing the first detection result obtained in advance with the second detection result. Of course, when the Landolt ring is presented at a random position, the first detection result can be obtained at each position.

In this embodiment, a configuration in which one Landolt ring is presented during subjective measurement or visual acuity testing of the subject's eye E has been described as an example, but the present invention is not limited to this. For example, multiple Landolt rings may be presented. As an example, multiple Landolt rings may be presented with the same visual acuity value but different slit directions. As another example, multiple Landolt rings may be presented with different visual acuity values but the same slit direction. As another example, multiple Landolt rings may be presented with different visual acuity values and different slit directions. These multiple Landolt rings may be arranged in accordance with the tilt direction of the answer lever 8a (response lever 303c).

In this case, the control unit may ask which Landolt ring is facing right, or which Landolt ring is most easily visible, etc. The control unit may also change the presentation state of the Landolt ring to the subject's eye E using answer information based on the signals input from each lever and line of sight information of the subject's eye E.

In this embodiment, the naked eye visual acuity of the subject's eye E may be measured using the subjective optometry device 100 of the first embodiment. In this case, for example, the display 61 may be placed at a position of 0D, which corresponds to infinity, and only step B of steps A to D may be performed. In step B, step B1 may be omitted, and steps B2 and onward may be performed in order.

In this embodiment, the vision testing device 300 of the second embodiment may be provided with a correction unit for correcting the refraction of the subject's eye E. For example, the correction unit may be provided in the optical path between the eyepiece 311 and the beam splitter 331. For example, the correction unit may have an optical element for correcting the subject's eye, and a motor for inserting and removing the optical element into and from the optical path. The optical element may be a lens, a prism, or the like.

Thereby, for example, the visual acuity testing device 300 may be used to measure the naked eye visual acuity of the test eye E and the corrected visual acuity when the test eye E is corrected. In other words, the naked eye visual acuity of the test eye E may be measured by removing an optical element in the optical path along which the visual target light beam from the visual target presenting unit 320 is guided to the test eye. Also, the corrected visual acuity of the test eye E may be measured by inserting an optical element in the optical path along which the visual target light beam from the visual target presenting unit 320 is guided to the test eye.

6 examiner's controller 10 control unit 20 subjective measurement optical system 50 observation optical system 60 light projection optical system 70 correction optical system 100 subjective optometry device 300 visual acuity measurement device 320 optotype presenting unit 330 anterior eye observation unit

Claims (4)

An optometry apparatus for presenting a test target to an eye to be examined and examining the eye to be examined, comprising:
A response input means for inputting the subject's interpretation of the test optotype;
an answer acquisition means for acquiring answer information related to the interpretation result based on an input signal from the answer input means;
an anterior ocular segment image acquiring means for acquiring an anterior ocular segment image of the subject's eye;
a line-of-sight information acquiring means for acquiring line-of-sight information regarding the line of sight of the subject's eye based on the anterior-segment image;
a change control means for changing a presentation state of the test target with respect to the subject's eye based on the answer information and the line of sight information;
Equipped with
a detection area is provided for each of the test optotypes to detect a coincidence between a position of the line of sight and a position of the test optotype;
The eye examination device is characterized in that the gaze information acquisition means acquires, as the gaze information, a determination result as to whether the test eye is gazing at the test target based on a first timing when the input signal is obtained from the answer input means and a second timing when the gaze position is included in the detection area . The optometric apparatus according to claim 1,
a target presenting means for presenting the test target to the subject's eye by emitting a target light beam toward the subject's eye,
The eye examination apparatus, wherein the change control means controls the optotype presenting means to change the presentation state of the test optotype so as to be different. The optometric apparatus according to claim 2,
a correction means for changing an optical characteristic of the visual target light beam in order to change a correction power for correcting the eye to be examined,
The optometry apparatus, wherein the change control means controls the correction means to change the correction power of the subject's eye to a different value. In the optometric apparatus according to claim 2 or 3,
A housing that houses the optotype presenting means;
a target window provided in the housing for confirming the test target presented inside the housing from outside the housing;
having
The answer input means is an answer input means for the subject to input an interpretation result of the subject peering into the optotype window and interpreting the test optotype,
The change control means changes the presentation state based on the correctness of the interpretation result and the line of sight information,
An optometry apparatus for automatically testing the visual acuity of the subject's eye.