JPS6258253B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an eye refractive power measurement device that automatically and precisely measures the refractive power of the eye, and in particular, the present invention relates to an eye refractive power measuring device that automatically and precisely measures the refractive power of the eye, and in particular, measures the diameter and area of the pupil of the eye to be examined at the same time or in parallel with the refractive power value measurement. The present invention relates to an eye refractive power measurement device that comprehensively grasps the refractive power of the eye and the accommodation state (correlation between pupil diameter and distance).

Manual eye refractometers have been used for a long time to measure the diopter of the eye as a basic ophthalmological test or when preparing glasses, but recently devices that automatically measure diopter have become popular. There is. Furthermore, recent technological trends regarding automatic eye refractometers have shifted to devices that require shorter measurement times or devices that provide more accurate measurements.

However, the measured values of this type of automatic eye refractometer are
It is inherently susceptible to the fixation state or accommodative state of the subject, and has the disadvantage of causing variations in measurement results for the subject's eye whose fixation or accommodative state is unstable.

On the other hand, in this type of conventional automatic eye refractometer,
It is difficult to clearly grasp the accommodative state of the eye to be examined, and there is a drawback that the reliability of the measurement results is reduced.

On the other hand, recent findings in bioengineering suggest that the pupil of the eye moves noticeably in response to light, and at the same time, pupillary reaction also occurs when the accommodative state of the eye shifts from far vision to near vision. and is attracting attention.

The present invention eliminates the drawbacks of the conventional devices described above, and at the same time makes it possible to accurately grasp the refractive power and accommodative state of the eye.The first purpose of the present invention is to measure refractive power and pupil diameter. The goal is to make it possible to implement both at the same time.

Furthermore, a second object of the present invention is to select a timing at which the accommodative state becomes stable using information on the measured pupil diameter value, and to automatically perform refractive power measurement at this timing, thereby obtaining a highly reliable refractive power value. The goal is to obtain measurement results.

An example of the configuration of an automatic eye refractometer will be described below, followed by a description of an example of the configuration of a pupil measurement system that characterizes the present invention.

In FIG. 1, E is the eye to be examined, Ef is the fundus or retina, Ep is the pupil, and Ec is the cornea. Reference numeral 1 is a fixation target, which is placed away from the subject using a dimming light source, a symbol, a picture, or the like.

2 is a dichroic mirror and the transmittance T is shown in Figure 2.
As an example of its characteristics, it reflects light with wavelengths longer than near-infrared, and transmits light with wavelengths shorter than that. 3 is the objective lens, dichroic mirror 2
The lens optical axis is arranged so as to coincide with the optical axis branched by. Reference numeral 4 indicates a portion related to projection and detection of the measurement pattern, which will be described later.

5 is a second dichroic mirror that reflects infrared light and transmits light with a shorter wavelength, as shown in FIG. 6 is a beam splitter, and 7 is a perforated lens having a hole 7a in the center. 8 is the aiming plate with a circular mark drawn in the center. 9 is a relay lens, 10 is an image pickup tube or image sensor array such as a vidicon, 11
is an infrared light emitting diode that illuminates the eye to be examined and is installed outside the housing.

Here, the front part of the eye to be examined, for example, the corneal surface Ec and the aiming plate 8.
The light-receiving surface of the image pickup tube 10 and the eye are in an optically conjugate relationship, and the image pickup tube 10 images the aiming mark superimposed on the front part of the subject's eye.

Next, 12 is a light emitting diode that emits light with a wavelength longer than near infrared, and 13 is a light shielding plate provided with a pinhole 13a, which serves as a positioning index. The light from the pinhole 13a enters the cornea in such a way that it forms an image at the corneal apex and half the center of curvature of the corneal surface (corresponding to the focal point of the convex mirror), where it is reflected and becomes a parallel beam of light, which is then passed through the objective lens. 3. Hole 7 of perforated lens 7
a and is imaged onto the aiming plate 8.

FIG. 4 shows a television receiver electrically coupled to a television camera including an image pickup tube 10. FIG. A display screen such as a cathode ray tube of the image receptor projects an image of the front part of the subject's eye, an aiming mark line 8a', and an alignment mark image 13a. However, in the case of Fig. 4, the alignment between the eye to be examined and the objective optical system is broken and the alignment mark image 13a' is blurred, indicating that the alignment between the eye to be examined and the objective optical system is inappropriate. Anyone can understand.

FIG. 5 shows that the alignment has been completed, and the aiming mark 8a' and the pupil of the eye to be examined are aligned concentrically, the alignment mark 13a' is located at the center of the aiming mark 8a', and a clear image is formed. After that, it becomes possible to measure.

Next, the eye refractive power measuring section will be explained with reference to FIG.

20 is an infrared light emitting diode, 21 is an aperture plate having a circular aperture 21a in the center, 22 is a condenser lens, and 23 is a deflection prism whose planar shape is 6th.
As shown in the figure, and as shown in FIG. 7 when viewed from the side, the beam is separated into three beams at each location 23a, 23b, and 23c. 24 is the 8th 3-beam slit plate.
As shown in the figure, it has three slits 24a, 24b, 24c perpendicular to the meridian that are 120 degrees apart from each other.

25 is a relay lens, and 26 is a three-hole plate, which has three openings 26a, 26b, 2 as shown in FIG.
6c is provided corresponding to each meridian.

A relay lens 27 is integrated with members 25 and 26 and is movable in the optical axis direction. 28 is a relay lens, and 29 is a perforated mirror having three openings 29a, 29b, and 29c shown in FIG. 10 corresponding to each meridian. 30 is a relay lens, 31 is a mirror, 32 is a relay lens, and 33 is a diaphragm plate having a circular aperture in the center. Numeral 34 is a relay lens which can be moved integrally with members 32 and 33 in the optical axis direction.As a result of selecting the combined refractive power of lenses 25 and 27 to be the same as that of lenses 32 and 34, both units are combined. It is monotonically transferred in one direction only once during one measurement by a transfer means (not shown).

35 is the same three-beam slit plate as shown in Fig. 8, and 36a, 36b, and 36c are light guides such as optical fiber bundles or acrylic light guide rods, and one end of each light guide is connected to each of the three-beam slit plates. It is placed in contact with the slit opening, and the other end is glued to a light receiving element such as a phototransistor. With the above optical arrangement, the three-beam slits 24 and 35 are always maintained conjugate with the fundus image with respect to the relaying members.

Further, 38 is a position detecting means having a length measuring device such as an encoder, which constantly detects the axial position of the above-mentioned movable unit during measurement.

Now, when the light emitting diode 20 is turned on, the infrared light illuminates the aperture plate 21, and the luminous flux emitted from the aperture 21a is transmitted through the condenser lens 20 to the three-beam slit plate 2.
Focus the light on 4. At that time, each slit 24a, 24b, 24c is
The light flux passing through the relay lens 25 is separated more effectively and subjected to a convergence effect by the relay lens 25. Each luminous flux is connected to a three-hole plate 26
The apertures 26a, 26b, and 26c prevent each light beam from interfering with each other. Next, the three light beams pass through the relay lens 27, form an image, and diverge.
The aperture 29 of the perforated mirror is converged by the relay lens 28.
a, 29b, and 29c, and after being reflected by the second dichroic mirror 5, it is re-imaged, further diverged, subjected to a converging action by the objective lens 3, and diverged by the dichroic mirror 2 to form the fundus. Attach the measurement pattern image to.

Now, assuming that the image coincides with the fundus Ef, the light beam scattered and reflected by the fundus exits the subject's eye and travels back along its original optical path, passing through the dichroic mirror 2.
The image is reflected by the second dichroic mirror 5, then reflected by the mirror surface of the perforated mirror 29, and then focused by the relay lens 30 behind the mirror 31. The image is then formed on the three-beam slit plate 35 via the relay lens 32, aperture diaphragm plate 33, and relay lens 34, and the light beams that have passed through each slit 35a, 35b, and 35c pass through the light guides 36a, 36b, and 36c. Light receiving element 3
7a, 37b, and 37c. At this time, if the image coincides with the fundus, the image of the measurement pattern slit of the three-beam slit plate 24 will accurately match the slit of the detection three-beam slit plate and will be clearly formed, so the amount of light received will be at its maximum. It will be a large amount. However, when the image is in front or behind the fundus Ef, the measurement pattern image formed on the detection three-beam slit is not only blurred, but also shifted in the meridian direction, so the amount of light received decreases. The reason why the image shifts in the meridian direction is that the imaging position is formed by an off-axis light beam that is off the optical axis. Movable units 25, 26, which move integrally in the optical axis direction with the start of measurement.
When the light receiving elements 27, 32, 33, and 34 are moved from their initial positions, the light receiving elements 37a, 37b, and 37c gradually increase, and the eye refractive power is detected from the amount of movement until reaching the maximum value. If there is astigmatism, the three light receiving elements will not detect the peak value at the same time, but will take the peak value one after another.

The output of the light receiving element is amplified by an amplifier and then peak detected by a peak detector, while the position detector 38 constantly inputs a position detection signal to an arithmetic processing circuit such as a microprocessor (not shown).

If measurements are made in the three meridian directions, the diopter is expressed as a function of the angle in the meridian direction by the following equation.

D=Asin(2θ-α)+B The variables D and θ represent diopter and meridian angle, respectively. Constants A, B, and α represent the degree of astigmatism (cylindrical diopter), average diopter (spherical diopter), and astigmatism axis direction, respectively.

Furthermore, the following display is possible. That is, average diopter (SPHERE) = A + B astigmatism (CYLINDER) = -2A astigmatism axis (AXIS) = α + 45 And the unit of each value is diopter, diopter, degree.

The results obtained in this manner are displayed on a television receiver as depicted in FIG.

FIG. 11 is a configuration diagram of a pupil diameter measuring circuit.

Reference numeral 48 denotes the above-mentioned television camera for imaging the front part of the subject's eye, and here it will be described as an example in which the pupil diameter of the subject's eye is measured by applying the processing described below to the video signal output from 48. . 5
0 is the sync separation circuit, 50a is V-SYNC, 50b
indicate H-SYNC, respectively. Reference numeral 61 denotes a video signal DC component regeneration circuit, which fixes the video signal to DC at every timing when the clamp pulse shown in 50c is input, and fixes the DC operating point against signal output fluctuations due to changes in subject brightness. The resulting video signal 61a is output. Reference numeral 62 denotes a binarization circuit, which inputs the video signal 61a, performs binary quantization on a preset DC slice level T (FIG. 12), and outputs a rectangular wave 62a. Here, in addition to the signal P corresponding to the pupil area as shown in FIG. 12, the rectangular wave 62a includes a signal P corresponding to the pupil area. Area detection includes an unnecessary signal N. In this embodiment, in order to remove the signal N, gating processing is performed using electronic window means. 63 is an electronic window control circuit which inputs V-SYNC and H-SYNC signals and outputs an electronic window pulse 63a. It is assumed that the area of the electronic window is fixed in advance in the area inside the broken line shown in FIG. As shown in the figure. In this case, it goes without saying that the center point of the area of the electronic window should match the imaging position of the optical axis center of the refraction measuring system due to the configuration of the present invention.

Next, the rectangular wave 62a is input to a gate circuit 66, ANDed with the electronic window pulse 63a described above, and shaped into a horizontal gate pulse 66a for the pupil. Reference numeral 67 denotes an integrating circuit which receives the horizontal gate pulse 66a of the pupil as an integral gate signal, and is configured so that the integral value is reset at each V-SYNC timing. Therefore, the integrating circuit 67 sequentially adds the horizontal recognition width of the pupil area in the vertical direction every cycle of one field of the video signal.
The output voltage of the integrating circuit 67 at the end of the integration corresponds to the area of the pupil region. Reference numeral 68 denotes a sample and hold circuit, which receives a sampling pulse from a pulse circuit (not shown) which outputs a gate pulse at the same time as the end of the vertical area of the electronic window, and is configured to sequentially hold the output voltage of the integration circuit 67. on the other hand,
Reference numeral 64 denotes a cursor control circuit for controlling the position of pupil diameter measurement, which inputs V-SYNC and H-SYNC signals and outputs a cursor pulse 64a once per field. 65 is a variable resistor that sets the vertical position of the cursor. The phase of the cursor pulse 64a in the horizontal cycle of the video signal is as shown in FIG.

The above-mentioned pupil horizontal gate pulse 66a is input to the gate circuit 69 together with the cursor pulse 64a, and by performing an AND operation, the horizontal gate pulse of the portion designated by the cursor pulse is selected, and the pupil diameter gate pulse is selected. 69a. Additionally, the cursor pulse 64a is connected to a video signal mixing circuit 49 to display a cursor marker as shown in FIG. 13 64b to facilitate confirmation of the selected vertical position.

70 is an integration circuit which inputs the pupil diameter gate pulse 69a as an integration gate signal, and outputs V-
The configuration is such that the integral value is reset at each SYNC timing. The gate pulse 69a is 1 as described above.
Since the signal is output only once during the field, the integrated output voltage of the integrating circuit 70 corresponds to the horizontal diameter of the pupil area. The output voltage of the integrating circuit 70 is connected to a sample and hold circuit 71, and is sequentially held at the timing of the end of the vertical area of the electronic window. A display 72 includes an analog-to-digital converter, and is configured to input the analog outputs of the sample and hold circuits 68 and 71, respectively, and digitally display the area and diameter values of the pupil.

In the above configuration, when the front part of the eye E to be examined is imaged with the television camera 48, a sawtooth signal corresponding to the area of the pupil is output as the output of the integrating circuit 67, and a cursor marker 6 is output as the output of the integrating circuit 70.
A sawtooth signal corresponding to the pupil diameter selected by 4b is output. The operations of both integrating circuits are repeated at the cycle of one field, and each includes unnecessary waveforms such as a falling waveform at the time of reset and a rising waveform at the time of integrating operation. The unnecessary waveforms are removed by the sample and hold circuits 68 and 71, and a signal whose DC level is maintained is input to the display 72 for each field. Therefore, the display 72 digitally displays the area and diameter values of the pupils sampled at the cycle of one field.

FIG. 14 is a block diagram of another embodiment of the present invention. This embodiment relates to a method for performing refractive power measurement when the pupil area reaches its maximum state.

100 indicates the pupil diameter measuring circuit described above, and 48
is a television camera, 68a is a pupil area signal, 50a
is the synchronization signal V-SYNC. 101 is an analog-to-digital converter, which outputs an analog signal 68a
and a synchronization signal 50a, and the pupil area signal is converted into digital data once per field. Reference numeral 102 denotes a storage circuit that sequentially stores and updates the digital data of the pupil area in one field period; in this case, the converter 101 and the storage circuit 102
The timing of the operation is controlled by a pulse circuit 108, and the memory circuit 102 is configured to constantly store and hold old pupil area data from one field ago. A comparator circuit 103 has a function of comparing the magnitude of data for two systems of data input. Here, it is assumed that the output data of the converter 101 is connected to input A, the data of one field previous held in the memory circuit 102 is connected to input B, and furthermore, the data of the converter 101 and the memory circuit 102 are connected from the pulse circuit 108. Input a mask pulse that inhibits the comparison operation of the comparator at the data update operation timing. The output of the comparator circuit 103 operates in three ways depending on the magnitude of the input data, and the contents will be explained using FIG. 15. 68a is a pupil area signal before digital conversion, which is a comparison sample signal in this case.
Note that the period of 68a, that is, the period of pupil movement, is generally one second to several seconds. The output 103a is an output that emits a signal when the input data becomes A=B, and corresponds to the extreme value states of minimum and maximum for the sample signal. The output 103b is a signal that is output when the input data is A<B, and according to the input connection described above, the data from the storage circuit 102 is larger than the data from the converter 101, that is, This corresponds to a state in which the data in the sample signal decreases over time. The output 103c is a signal output when the input data is A>B, and when the input data is larger than the data of the converter 101 and the data of the storage circuit 102, the time elapsed in relation to the sample signal. The data is increasing.

Therefore, the comparator circuit with the above input connection has the function of calculating the time differential of the sample signal, and when the differential coefficient of the sample signal is 0, it is 10
3a is output, 103b is output when the differential coefficient is similarly negative, and 103c is output when the differential coefficient is positive. 10
5 is a trigger circuit that controls the start of measurement of the refractive power measuring section. A configuration including a circuit for detecting a falling edge portion of an input signal and a gate circuit,
Trigger pulse 1 by inputting the output 103c of the comparator circuit and the command of the refractive power measurement switch 104.
Outputs 05a. In this case, trigger pulse 1
As shown in FIG. 15, the timing at which signal 05a is output is when the falling edge section 103c is selected while the switch command 104a is input, and at this point, the sample signal, that is, the pupil area signal 68a is This coincides with the timing that gives the maximum value.

106 is a lighting circuit for the light source 20 of the refractive power measuring section;
Reference numeral 107 indicates a drive circuit for moving the relay lens of the refractive power measurement unit.The output 105a from the trigger circuit 105 described above is input to 106 and 107, and the refractive power is measured at the timing when the trigger pulse 105a is generated. The lighting of the light source 20 and the driving of the relay lens movement are started.

In the above configuration, when the front part of the eye E to be examined is imaged by the television camera 48, the measurement circuit 100 measures the area and diameter of the pupil region of the eye E, and an analog signal of the pupil area is output to the output 68a. be done. The output of 68a is further used by a comparator circuit having a differentiation function to recognize signals corresponding to the maximum and minimum states of the pupil area that change over time. These series of signal processing are executed continuously during the process in which the examiner aligns the eye to be examined for refractive power measurement, but until the examiner presses the measurement switch 104, the trigger circuit 104
The gate circuit 5 is kept in an inhibited state by the signal 104a, and the trigger pulse 105a for starting refraction measurement is not output. When the examiner completes the alignment of the eye to be examined and presses the measurement switch 104, the trigger circuit 105 becomes enabled, and the trigger pulse 105a is output at the timing when the pupil area reaches its maximum, turning on the light source 20 and turning on the relay. A lens transfer is performed and a refractive power measurement is performed.

In the above-described embodiment, the refractive power measurement is performed in synchronization with the time when the pupil area reaches the maximum state, but if the refractive power measurement is to be performed when the pupil area reaches the minimum state, the signal to the trigger circuit 105 is 103b may be used as an input. Further, in the above embodiment, the execution of the refractive power measurement is controlled in accordance with the differential value of the pupil area, but if the execution of the refractive power measurement is controlled by the differential coefficient of the measured value of the pupil diameter, the converter 101 71a as an input signal to
You can use .

Furthermore, in this embodiment, the storage circuit in the data comparison section of the differential calculation means is configured for one data, but by storing and holding a plurality of data sequentially in time, and performing the data size comparison multiple times, It also becomes possible to detect extreme values of slow frequency cycles.

FIG. 16 is a block diagram of another embodiment of the present invention. This embodiment relates to a method of printing, using a printer, the pupil area value at the time when the refractive power measurement is performed together with the refractive power measurement value.

In the figure, numerals 48 and 100 are the same as in the previous embodiment. Reference numeral 110 denotes a storage circuit including an analog-to-digital converter, which inputs the pupil area signal from the sample-and-hold circuit 68, and updates and holds the digital data of the pupil area at the time when the synchronization pulse 111a is generated. A synchronous pulse output circuit 111 receives the state of the refractive power measurement switch 104 and outputs a synchronous pulse 111a instructing execution of refractive power measurement. The synchronizing pulse 111a is further applied to the light source lighting circuit 10.
6 and the relay lens transfer drive circuit 107 to perform refractive power measurement in the same manner as in the previous embodiment. 47 is a microprocessor, 54 is a printer, and 54a is a release button.
The data stored in the memory circuit 110 is input to the microprocessor 47, and the data is input to the microprocessor 47 along with the refractive power measurement data executed at that time.
7 memory area. When the release button 54a is pressed at this stage, the microprocessor 47 outputs the pupil area value and the measured refractive power as a set of data, and the printer 54 outputs the measured refractive power value and the measured refractive power value at the time when the refractive power measurement was performed. The pupil area value is also printed.

FIG. 17 is a block diagram of still another embodiment of the present invention, which relates to a method of simultaneously recording the timing of execution of refractive power measurement on a recorder that records analog changes in the area and diameter of the pupil over time.

120, 121, 122 are buffer amplifiers, 1
Reference numerals 23 indicate recorders that simultaneously perform analog recording of a plurality of signals. Batsuhua amp 120
The pupil area signal output from 68 is input to , the pupil diameter signal output from 71 is input to buffer amplifier 121 , and the pupil diameter signal output from 71 is input to buffer amplifier 121 .
2 is configured to input the synchronization pulse 111a explained in the above embodiment from the synchronization pulse output circuit 111 and simultaneously record the respective signal waveforms on the recorder 123.

With the configuration of this embodiment, it is possible to record the reaction state of the pupil of the subject's eye over a long period of time, and it is also possible to simultaneously record the timing of refractive power measurement.

As explained above, by measuring the pupil diameter of the subject's eye using the output signal of the television camera attached to the refractive power measurement device for imaging the front part of the subject's eye, refractive power and pupil diameter measurements can be performed simultaneously. becomes executable.

Furthermore, the information on the pupil diameter measurement value can be used to control or evaluate refractive power measurement, which has the effect of facilitating highly reliable refractive power measurement.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram of the eye refractive power measurement device, Figure 2
Figure 3 is a transmission characteristic diagram of the dichroic mirror, Figures 4 and 5 are front views of the image receptor, Figures 6 and 7 are illustrations of the deflection prism, and Figure 8 is a diagram of the three-beam slit plate. Explanatory diagram, Figure 9 is an explanatory diagram of the three-hole plate, Figure 10
11 is an explanatory diagram of a perforated mirror, FIG. 11 is a configuration diagram of a first embodiment of a pupil diameter measuring circuit according to the present invention, and FIG.
13 is a waveform diagram of each part of the first embodiment of the pupil diameter measuring circuit according to the present invention; FIG. 13 is a diagram of the television receiver when the first embodiment of the pupil diameter measuring circuit according to the present invention is in operation; FIG. 14 is a block diagram of the second embodiment of the present invention, FIG. 15 is a waveform diagram of each part of the second embodiment of the present invention, and FIG. 16 is a block diagram of the third embodiment of the present invention.
FIG. 17 is a configuration diagram of a fourth embodiment of the present invention, in which 8 is a sighting plate, 10 is an image pickup tube, 13 is a light shielding plate, 13
a is a pinhole, 23 is an angle prism, 24 is 3
Luminous flux slit plate, 26 is a three-hole plate, 29 is a perforated mirror,
37a, 37b, 37c are light receiving elements, 38 is a position detecting means, 48 is a television camera, 62 is a binarization circuit, 63 is an electronic window control circuit, 64 is a cursor control circuit, 67, 70 is an integrating circuit, 68, 71 101 is a sample hold circuit, 101 is an analog/digital converter, 102 is a storage circuit, 103 is a comparator circuit, 110 is a storage circuit, 111 is a synchronous pulse output circuit, and 123 is a recorder.

Claims (1)

[Claims] 1. An index projection system that projects an index onto the fundus of the eye to be examined;
In an eye refractive power measurement apparatus having a light receiving system that receives an index light reflected from the fundus of the eye to be examined to obtain eye refractive power information, and an anterior eye segment observation system that allows the anterior eye segment of the eye to be examined to be observed with a scanning imaging unit. , extracting a rectangular wave corresponding to the size of the pupil of the eye to be examined from the output signal of the imaging unit 2
a value converting means, a pupil diameter measuring means for measuring the size of the pupil based on the width of the rectangular wave, a differential calculating means for calculating a time differential value for the output data of the pupil diameter measuring means; It is characterized by comprising a trigger control means for emitting a trigger pulse when the output of the differential calculation means reaches a predetermined value, and measuring the refractive power of the eye to be examined in synchronization with the output of the trigger control means. Eye refractive power measuring device. 2. An index projection system that projects an index onto the fundus of the eye to be examined;
In an eye refractive power measurement apparatus having a light receiving system that receives an index light reflected from the fundus of the eye to be examined to obtain eye refractive power information, and an anterior eye segment observation system that allows the anterior eye segment of the eye to be examined to be observed with a scanning imaging unit. , extracting a rectangular wave corresponding to the size of the pupil of the eye to be examined from the output signal of the imaging unit 2
a value converting means, a pupil diameter measuring means for measuring the size of the pupil based on the width of the rectangular wave, a differential calculating means for calculating a time differential value for the output data of the pupil diameter measuring means; and trigger control means for emitting a trigger pulse when the output of the differential calculation means reaches a predetermined value, and measures the refractive power of the eye to be examined in synchronization with the output of the trigger control means, and further measures the pupil diameter. A pupil diameter storage means that stores and holds output data of the measurement means, a synchronous pulse output means that outputs a pulse in synchronization with the timing of execution of refractive power value measurement, and a record that records the eye refractive power value and the measured pupil diameter value. and updating the data held in the pupil diameter storage means according to the timing of the synchronization pulse, and digitally records both the data held in the pupil diameter storage means and the measured data of the eye refractive power value. Features of the eye refractive power measuring device. 3 an index projection system that projects an index onto the fundus of the eye to be examined;
In an eye refractive power measuring device having a light receiving system that receives an index light reflected from the fundus of an eye to be examined to obtain eye refractive power information, and an anterior eye segment observation system that allows the anterior eye segment of the eye to be examined to be observed with a scanning type imaging unit. , extracting a rectangular wave corresponding to the size of the pupil of the eye to be examined from the output signal of the imaging unit 2
a value converting means, a pupil diameter measuring means for measuring the size of the pupil based on the width of the rectangular wave, a differential calculating means for calculating a time differential value for the output data of the pupil diameter measuring means; and a trigger control means that emits a trigger pulse when the output of the differential calculation means reaches a predetermined value, measures the refractive power of the eye to be examined in synchronization with the output of the trigger control means, and further measures the refractive power value. A synchronous pulse output means that outputs a pulse in synchronization with the timing of measurement execution, and a recording means that performs analog recording of a pupil diameter measurement value, the analog output of the pupil diameter measurement means and the pulse of the synchronous pulse output means are provided. An eye refractive power measuring device characterized in that it records waveforms as well.