JP7600794B2 - Visual field evaluation device and visual field evaluation method - Google Patents

Description

The present invention relates to a visual field evaluation device.

A visual field evaluation device is known that displays an index on a display unit to detect the subject's line of sight and evaluates the subject's visual field based on the detection results (see, for example, Patent Document 1).

Patent No. 6606264

When using a visual field evaluation device such as the one described above for evaluation, characteristics such as sensitivity to indicators and response speed may differ from subject to subject. Therefore, it is necessary to evaluate the visual field according to the subject's characteristics.

The present invention has been made in consideration of the above, and aims to provide a visual field assessment device that can assess the visual field according to the characteristics of the subject.

The visual field evaluation device according to the present invention includes a display unit, a viewpoint detection unit that detects the position of the subject's viewpoint on the display unit, a display control unit that sets the position on the display unit where the subject's viewpoint is detected as a reference position and displays an index at a position on the display unit away from the reference position, and an evaluation unit that evaluates the display position of the index as being included in the subject's visible area centered on the reference position when the subject's viewpoint moves to the display position of the index, and evaluates the display position of the index as not being included in the visible area when the subject's viewpoint does not move to the display position of the index. When the display and evaluation of the index are performed multiple times in succession, the display control unit displays the index in a first mode in which the subject has a higher visual difficulty than the previous evaluation if the display position of the index is evaluated to be included in the visible area in the previous evaluation, and displays the index in a second mode in which the visual difficulty is lower than the previous evaluation if the display position of the index is evaluated to be not included in the visible area in the previous evaluation.

The present invention provides a visual field assessment device that can assess the visual field according to the characteristics of the subject.

FIG. 1 is a diagram showing an example of a visual field evaluation device according to the present embodiment. FIG. 2 is a functional block diagram showing an example of a visual field evaluation device. FIG. 3 is a diagram showing an example of the display content on the display unit. FIG. 4 is a diagram showing an example of the display content on the display unit. FIG. 5 is a diagram showing an example of the display content on the display unit. FIG. 6 is a diagram showing an example of the display content on the display unit. FIG. 7 is a diagram showing an example of the display content on the display unit. FIG. 8 is a diagram showing an example of the display content on the display unit. FIG. 9 is a diagram showing an example of the display content on the display unit. FIG. 10 is a diagram showing an example of the display content on the display unit. FIG. 11 is a diagram showing an example of the display content on the display unit. FIG. 12 is a flowchart showing an example of a visual field evaluation method according to this embodiment. FIG. 13 is a diagram showing an example of display content on the display unit in the modified example.

Below, an embodiment of the visual field assessment device according to the present invention will be described with reference to the drawings. Note that the present invention is not limited to this embodiment. Furthermore, the components in the following embodiment include those that are easily replaceable by a person skilled in the art, or those that are substantially the same.

Figure 1 is a diagram showing an example of a visual field assessment device 100 according to this embodiment. The visual field assessment device 100 shown in Figure 1 detects the gaze of a subject and evaluates the subject's visual field by using the detection result. The visual field assessment device 100 can detect the subject's gaze using various methods, such as a method of detecting the gaze based on the position of the subject's pupil and the position of the corneal reflection, or a method of detecting the gaze based on the position of the subject's inner corner of the eye and the position of the iris.

As shown in FIG. 1, the visual field evaluation device 100 includes a display device 10, an eyeball imaging device 20, and a control device 30.

The display device 10 includes a flat panel display such as a liquid crystal display (LCD) or an organic electroluminescence display (OLED). In this embodiment, the display device 10 has a display unit 11. The display unit 11 displays information such as images. The display device 10 may be a head-mounted display device. When the display device 10 is a head-mounted display device, a configuration such as an eye imaging device 20 is disposed within a head-mounted module.

The eyeball photographing device 20 photographs the left and right eyeballs EB of the subject to obtain eyeball images, and transmits the obtained eyeball images to the control device 30. The eyeball photographing device 20 photographs the left and right eyeballs EB of the subject to obtain image data. The eyeball photographing device 20 has various cameras according to the method of detecting the subject's line of sight. For example, in the case of a method of detecting the line of sight based on the position of the subject's pupil and the position of the corneal reflection image, the eyeball photographing device 20 has an infrared camera, and has an optical system that can transmit near-infrared light with a wavelength of 850 [nm], for example, and an image sensor that can receive the near-infrared light. Note that this configuration may be configured to include an irradiation device that irradiates the subject's eyeball EB with infrared rays. Also, in the case of a method of detecting the line of sight based on the position of the subject's inner corner and the position of the iris, for example, the eyeball photographing device 20 has a visible light camera. The eyeball photographing device 20 outputs a frame synchronization signal. The period of the frame synchronization signal can be, for example, 20 [msec], but is not limited to this. The eyeball imaging device 20 can be configured as, for example, a stereo camera having two cameras, but is not limited to this.

The control device 30 comprehensively controls the operation of the visual field evaluation device 100. The control device 30 includes an arithmetic processing device such as a CPU (central processing unit) and a storage device such as a memory or storage device, such as a ROM (read only memory) and a RAM (random access memory). The control device 30 causes the arithmetic processing device to carry out arithmetic processing according to a computer program stored in the storage device.

In the visual field evaluation device 100 according to this embodiment, the display device 10 and the control device 30 are separate devices. The display device 10 and the control device 30 may be integrated. For example, the visual field evaluation device 100 may include a tablet-type personal computer. In this case, the tablet-type personal computer may be equipped with a display device, an eyeball imaging device, a computer system, an input device, an output device, etc.

Figure 2 is a functional block diagram showing an example of a visual field evaluation device 100. As shown in Figure 2, the control device 30 has a display control unit 31, a viewpoint detection unit 32, a determination unit 33, a calculation unit 34, an evaluation unit 35, and a memory unit 36.

The display control unit 31 causes the display unit 11 to display an index for the subject to gaze at. The display control unit 31 can control the brightness of the index in multiple stages. The display control unit 31 may also be capable of controlling the size of the index and the display time for displaying the index in multiple stages.

The display control unit 31 sets the position on the display unit 11 where the subject's gaze point is detected as a reference position, and displays an index at a position on the display unit 11 away from the reference position. The display control unit 31 displays the index at an appropriate position when evaluating the subject's visual field. The display control unit 31 may calculate the appropriate position based on evaluation information stored in the memory unit 36 after performing past measurements, for example.

When performing continuous measurements, the display control unit 31 sets a new reference position on the display unit 11 at which the subject's gaze point is detected after the evaluation unit 35 has performed the previous evaluation. If the display position of the index is evaluated to be within the visible area in the previous evaluation, the display control unit 31 displays the index in a first manner that is more difficult for the subject to see than in the previous evaluation. If the display position of the index is evaluated to be not within the visible area in the previous evaluation, the display control unit 31 displays the index in a second manner that is more difficult for the subject to see than in the previous evaluation.

Here, visual difficulty refers to the degree of difficulty in visually recognizing an index when the reference position is the center of the visual field of the subject. For example, the further the display position of the index is from the reference position, the lower the luminance of the index, the smaller the size of the index, and the shorter the display time of the index, the higher the visual difficulty. Conversely, the closer the display position of the index is from the reference position, the higher the luminance of the index, the larger the size of the index, and the longer the display time of the index, the lower the visual difficulty.

Therefore, examples of the first aspect include an aspect in which the indicator is displayed at a position where the distance between the reference position and the display position of the indicator is longer than in the previous display, an aspect in which the indicator is displayed with a lower brightness than in the previous display, an aspect in which the indicator is displayed with a smaller size than in the previous display, and an aspect in which the indicator is displayed for a shorter display time than in the previous display.

The second aspect may be, for example, a feature in which the indicator is displayed at a position where the distance between the reference position and the indicator display position is shorter than in the previous display, a feature in which the indicator is displayed with a higher brightness than in the previous display, a feature in which the indicator is displayed with a larger size than in the previous display, or a feature in which the indicator is displayed for a longer period of time than in the previous display.

The first aspect may be an aspect in which the index is displayed so that the greater the difficulty of visibility of the index in the immediately preceding session, or the shorter the time it takes for the subject's gaze to reach the display position of the index in the immediately preceding session, the greater the difficulty of visibility. For example, as the first aspect, the display control unit 31 may display the index at a position farther from the reference position, or at a lower brightness, as the lower the brightness of the index in the immediately preceding session. Also, as the first aspect, the display control unit 31 may display the index at a position farther from the reference position, or at a lower brightness, as the shorter the time it takes for the subject's gaze to reach the display position of the index in the immediately preceding session.

The viewpoint detection unit 32 detects the position of the subject's viewpoint. In this embodiment, the viewpoint detection unit 32 detects the subject's gaze vector defined in a three-dimensional global coordinate system based on images of the subject's left and right eyes EB acquired by the eyeball imaging device 20. The viewpoint detection unit 32 detects the position of the intersection between the detected gaze vector of the subject and the display unit 11 of the display device 10 as the position of the subject's viewpoint. In other words, in this embodiment, the position of the viewpoint is the position of the intersection between the gaze vector of the subject defined in a three-dimensional global coordinate system and the display unit 11 of the display device 10. The viewpoint detection unit 32 detects the position of the subject's gaze position at every specified sampling period. This sampling period can be, for example, the period of the frame synchronization signal output from the eyeball imaging device 20 (for example, every 20 [msec]).

The determination unit 33 determines whether or not the viewpoint is present in the determination area corresponding to the index based on the position of the viewpoint during the period in which the index is displayed by the display control unit 31, and outputs the determination result. The determination area is, for example, an area that includes the index, and can be set along the contour of the index. The determination unit 33 determines whether or not the viewpoint is present in the determination area at each specified determination period. The determination period can be, for example, the period of the frame synchronization signal output from the eye imaging device 20 (for example, every 20 msec). In other words, the determination period of the determination unit 33 is the same as the sampling period of the viewpoint detection unit 32. The determination unit 33 makes a determination about the viewpoint each time the viewpoint position is sampled by the viewpoint detection unit 32, and outputs the determination result.

The calculation unit 34 has a timer that detects the time that has elapsed since the index was displayed on the display unit 11, and a counter that counts the number of times that the determination unit 33 has determined that the gaze point exists in the determination area. For example, when the counter value exceeds a predetermined threshold, the calculation unit 34 can detect that the subject's gaze point has moved to the index. Furthermore, the calculation unit 34 can calculate the arrival time from when the index is displayed until the subject's gaze point moves to the index, based on the timer.

The evaluation unit 35 evaluates the subject's visible area based on the position of the subject's viewpoint. For example, if the subject's viewpoint moves to the display position of the index, the evaluation unit 35 evaluates that the display position of the index is included in the subject's visible area centered on the reference position. In addition, for example, if the subject's viewpoint does not move to the display position of the index, the evaluation unit 35 evaluates that the display position of the index is not included in the visible area.

The storage unit 36 stores the above-mentioned judgment results and evaluation results. The storage unit 36 also stores a visual field evaluation program that causes a computer to execute the following processes: a process of displaying an index at a position on the display unit 11 away from the reference position, with the position on the display unit 11 where the subject's gaze point is detected as a reference position; a process of evaluating the display position of the index as being included in the subject's visible area centered on the reference position when the subject's gaze point moves to the display position of the index, and evaluating the display position of the index as not being included in the visible area when the subject's gaze point does not move to the display position of the index; and a process of displaying the index in a first mode in which the subject has a higher degree of difficulty in viewing than in the previous evaluation when the display and evaluation of the index are performed multiple times in succession, if the display position of the index is evaluated to be included in the visible area in the previous evaluation, and if the display position of the index is evaluated to be not included in the visible area in the previous evaluation, the display of the index in a second mode in which the subject has a lower degree of difficulty in viewing than in the previous evaluation.

Next, a visual field evaluation method according to this embodiment will be described. In the visual field evaluation method according to this embodiment, the visual field evaluation device 100 described above is used to evaluate the visual field of the subject.

Figures 3 to 11 are diagrams showing an example of the display content on the display unit 11. As shown in Figure 3, the display control unit 31 displays a reference index P so that the subject's gaze is directed toward, for example, the center of the display unit 11. The gaze point detection unit 32 detects the position of the subject's gaze point. The judgment unit 33 judges whether or not the detected gaze point of the subject is present in a judgment area corresponding to the reference index P.

When the determination unit 33 determines that the viewpoint is in the determination area, the display control unit 31 sets the display position (X0, Y0) of the reference indicator P as the reference position, and displays the indicator Q at a predetermined brightness at a position away from the position of the reference indicator P, which is the reference position, as shown in FIG. 4. For example, on the display unit 11, the display control unit 31 can randomly select one area from four areas, a first area 11A corresponding to the first quadrant when the reference position is set as the origin, a second area 11B corresponding to the second quadrant, a third area 11C corresponding to the third quadrant, and a fourth area 11D corresponding to the fourth quadrant, to display the indicator Q.

The viewpoint detection unit 32 detects the position of the subject's viewpoint. The judgment unit 33 judges whether the detected subject's viewpoint is in the judgment area, that is, the area corresponding to the index Q. The calculation unit 34 calculates the time during which the subject's viewpoint is in the area corresponding to the index Q based on the judgment result. If the calculated time is equal to or longer than a predetermined time, the evaluation unit 35 judges that the subject's viewpoint has moved to the display position of the index Q. If the evaluation unit 35 judges that the subject's viewpoint has moved to the display position of the index Q, it evaluates that the display position of the index Q is included in the subject's visible area centered on the reference position. Furthermore, if the calculated time is less than a predetermined time, the evaluation unit 35 judges that the subject's viewpoint has not moved to the display position of the index Q. If the evaluation unit 35 judges that the subject's viewpoint has not moved to the display position of the index Q, it evaluates that the display position of the index Q is not included in the subject's visible area centered on the reference position. After performing an evaluation of the visible area centered on the reference position, the evaluation unit 35 associates the position of the index Q with the evaluation content and stores it in the storage unit 36.

When the display and evaluation of the above indices are performed multiple times in succession, the display control unit 31 causes the reference index P to be displayed again, for example, in the center of the display unit 11. In this case, the display position of the reference index P is not limited to the center of the display unit 11, and may be another position. The viewpoint detection unit 32 detects the position of the subject's viewpoint. The judgment unit 33 judges whether or not the detected subject's viewpoint is present in the judgment area corresponding to the reference index P.

When the determination unit 33 determines that the viewpoint is in the determination area, the display control unit 31 displays the index with the display position of the reference index P as the reference position. When the display control unit 31 determines that the display position of the index Q is included in the visible area in the previous evaluation, the display control unit 31 displays the index Q1 in a first mode with a higher visual difficulty than the previous evaluation, as shown in FIG. 5. As shown in FIG. 5, the display control unit 31 can display the index Q1 in the first mode, for example, at a position that is farther away from the reference position than the previous evaluation. Note that, as in the previous evaluation, when displaying the index Q1, one area can be randomly selected from the four areas (first area 11A, second area 11B, third area 11C, fourth area 11D) on the display unit 11 and displayed. Note that the display control unit 31 may display a new index in an area of the four areas that is different from the area in which the index Q was displayed in the previous evaluation.

Furthermore, when the display position of the index Q is evaluated as not being included in the visible area in the immediately preceding evaluation, the display control unit 31 displays the index Q2 in a second mode in which the visibility difficulty is lower than in the immediately preceding evaluation, as shown in Fig. 6. As shown in Fig. 6, the display control unit 31 can display the index Q2 in the second mode, for example, at a position where the distance from the reference position is shorter than in the immediately preceding evaluation.

Examples of the first and second aspects are not limited to the examples shown in Figs. 5 and 6. For example, as shown in Fig. 7, the display control unit 31 may display, as the first aspect, an index Q3 with a lower brightness than the index Q of the previous time. In this case, the distance between the reference position and the index Q3 may be the same as the distance between the reference position and the index Q of the previous time.

As shown in FIG. 8, the display control unit 31 may display, as a second mode, an index Q4 with a higher brightness than the immediately preceding index Q. In this case, the distance between the reference position and index Q4 may be the same as the distance between the reference position and index Q in the immediately preceding time.

In addition, as a first mode, the display control unit 31 can display the indices in a mode in which the more difficult it is to see the more difficult it is to see the indices in the previous time. FIG. 9 shows an example in which the display positions of the indices Q5, Q6, and Q7 in the previous time are evaluated to be included in the visible area. As shown in FIG. 9, the lower the luminance of the indices Q5, Q6, and Q7, the more the display control unit 31 can display the indices Q8, Q9, and Q10 in positions farther from the reference position. For example, for the index Q5 with a medium luminance, the display control unit 31 can display the index Q8 in a position with a medium distance from the reference position. For the index Q6 with a lower luminance than the index Q5, the display control unit 31 can display the index Q9 in a position farther from the reference position than the index Q8. For the index Q7 with a higher luminance than the index Q5, the display control unit 31 can display the index Q10 in a position closer to the reference position than the index Q8.

In addition, as a first aspect, the display control unit 31 can display the index so that the visual difficulty increases as the time it takes for the subject's gaze to reach the index in the immediately preceding time is shorter. For example, as shown in FIG. 10, the calculation unit 34 calculates the time t for the subject's gaze to reach index Q11 in the immediately preceding time. When the time t is time t1 that is longer than a predetermined threshold, the display control unit 31 displays index Q12 at a position based on the reference position. On the other hand, when the time t is time t2 that is shorter than the predetermined threshold, the display control unit 31 can display index Q13 at a position farther away than index Q12 with respect to the reference position. Note that the display control unit 31 may display index Q13 with a lower brightness than index Q12.

In addition, in each of the above explanations, the reference position is set to the same position as in the previous display (the center position of the display unit 11), but this is not limiting. For example, as shown in FIG. 11, if the display control unit 31 displayed index Q14 with reference index P1 as the reference position in the previous display, the display position of index Q14 may be set as a new reference position to display index Q15. In this case, reference index P2 may be displayed at the newly set reference position.

When the indices (Q1 to Q4, Q8 to Q10, Q12, Q13, Q15) are displayed as described above, the viewpoint detection unit 32 detects the position of the subject's viewpoint, as in the case of displaying the indices (Q, Q5 to Q7, Q11, Q14) the previous time. The determination unit 33 determines whether the detected subject's viewpoint is present in the determination area, that is, the area corresponding to the indices. The calculation unit 34 calculates the time during which the subject's viewpoint is present in the area corresponding to the indices, based on the determination result. The evaluation unit 35 determines that the subject's viewpoint has moved to the display position of the indices if the calculated time is equal to or longer than a predetermined time. If the evaluation unit 35 determines that the subject's viewpoint has moved to the display position of the indices, it evaluates that the display position of the indices is included in the subject's visible area centered on the reference position. Furthermore, if the calculated time is less than the predetermined time, the evaluation unit 35 determines that the subject's viewpoint has not moved to the display position of the indices. If the evaluation unit 35 determines that the subject's viewpoint has not moved to the display position of the indices, it evaluates that the display position of the indices is not included in the subject's visible area centered on the reference position. The evaluation unit 35 evaluates the visible area centered on the reference position, and then stores the index position and the evaluation content in the memory unit 36 in association with each other.

After that, if the display control unit 31 evaluates that the display position of the marker is included in the visible area, it sets a new reference position and displays the new marker in a first manner in which the subject has a higher degree of difficulty in viewing than the marker for the new reference position. If the display control unit 31 evaluates that the display position of the marker is not included in the visible area, it displays the new marker in a second manner in which the subject has a lower degree of difficulty in viewing than the marker for the new reference position. Then, by having the subject gaze at the new marker in the same manner as above, it evaluates whether the display position of the new marker is included in the subject's visible area, and stores the evaluation result in the storage unit 36. In this way, the manner of the marker to be displayed next is changed based on the evaluation content of the marker displayed immediately before, and visual field measurement and evaluation are performed.

By multiple measurements and evaluations, the memory unit 36 accumulates information on positions that are evaluated to be included in the subject's visible area. The evaluation unit 35 may map the subject's visible area based on this accumulated position information and display the mapping result on the display unit 11 or the like. The memory unit 36 also accumulates information on positions that are evaluated to be not included in the subject's visible area. When displaying an index on the display unit 11, the display control unit 31 may weight the random number so that the number of times that an index is displayed increases for an area corresponding to a position that is evaluated to be not included in the subject's visible area among the four areas from the first area 11A to the fourth area 11D. The evaluation unit 35 may also generate a database that associates each piece of position information accumulated in the memory unit 36 with additional information such as the subject's age, sex, and occupation. The evaluation unit 35 may determine the association between the subject's additional information and the evaluation result of the visible area based on the database.

Next, an example of a visual field evaluation method according to this embodiment will be described with reference to FIG. 12. FIG. 12 is a flowchart showing an example of a visual field evaluation method according to this embodiment. In this embodiment, the display control unit 31 sets a position on the display unit 11 where the subject's gaze point is detected as a reference position (step S10). The display control unit 31 displays an index at the reference position (step S20).

The viewpoint detection unit 32 detects the position of the subject's viewpoint (step S30). Based on the detected viewpoint position, the evaluation unit 35 evaluates whether the display position of the index is included in the subject's visible area centered on the reference position (step S40), and stores the evaluation result in the storage unit 36 in association with the display position of the index (step S50). After step S50, if the measurement of the visual field is to be ended, the subsequent processing is skipped and the processing is ended (Yes in step S60).

After completing the visual field measurement, the measurement results may be output. Possible output formats for the measurement results include printing them on paper or displaying them on a display device. For example, if the measurer prints the measurement results on paper or displays them on a display device, it becomes easier to explain the measurement results to the subject.

If the visual field measurement is not to be ended (No in step S60), the display control unit 31 sets the position on the display unit 11 where the subject's gaze point is detected as a new reference position (step S70). If the display position of the index was evaluated to be included in the visible area in the immediately preceding measurement (Yes in step S80), the display control unit 31 displays the index in the first mode (step S90). On the other hand, if the display position of the index was evaluated to be not included in the visible area in the immediately preceding measurement (No in step S80), the display control unit 31 displays the index in the second mode (step S100). After step S90 or step S100, the processing from step S30 onwards is performed.

As described above, the visual field evaluation device 100 according to this embodiment includes the display unit 11, the viewpoint detection unit 32 that detects the position of the subject's viewpoint on the display unit 11, the display control unit 31 that sets the position on the display unit 11 where the subject's viewpoint is detected as a reference position and displays an index at a position away from the reference position, and the evaluation unit 35 that evaluates that the display position of the index is included in the subject's visible area centered on the reference position when the subject's viewpoint moves to the display position of the index, and evaluates that the display position of the index is not included in the visible area when the subject's viewpoint has not moved to the display position of the index. When the display and evaluation of the index are performed multiple times in succession, if the display position of the index is evaluated to be included in the visible area in the previous evaluation, the display control unit 31 displays the index in a first mode that is more difficult for the subject to see than in the previous evaluation, and if the display position of the index is evaluated to be not included in the visible area in the previous evaluation, the display control unit 31 displays the second index in a second mode that is more difficult to see than in the previous evaluation.

With this configuration, the display unit 11 changes the format of the next indicator to be displayed based on the evaluation content of the indicator displayed on the display unit 11 the previous time, making it possible to evaluate the visual field according to the characteristics of the subject.

In the visual field evaluation device 100 according to this embodiment, the first mode is a mode in which the index is displayed at a position where the distance between the reference position and the display position of the index is longer than in the previous display, and the second mode is a mode in which the index is displayed at a position where the distance between the reference position and the display position of the index is shorter than in the previous display. With this configuration, the position of the index to be displayed next can be changed depending on whether the index displayed last time was within the visible area, thereby enabling efficient mapping of the visible area.

In the visual field evaluation device 100 according to this embodiment, the display control unit 31 controls the brightness of the index in multiple stages for display, with the first mode being a mode in which the index is displayed at a lower brightness than the immediately preceding display, and the second mode being a mode in which the index is displayed at a higher brightness than the immediately preceding display. With this configuration, the brightness of the index to be displayed next can be changed depending on whether the index displayed immediately preceding was within the visible area, thereby enabling highly accurate mapping of the visible area.

In the visual field assessment device 100 according to this embodiment, the display control unit 31 controls the brightness of the markers in multiple stages for display, and the first mode includes a mode in which the lower the brightness of the marker in the previous display, the farther the marker is displayed from the reference position. With this configuration, the position of the marker to be displayed next can be changed according to the visual difficulty of the marker that was evaluated to be included in the visible area in the previous display, thereby enabling efficient mapping of the visible area.

In the visual field assessment device 100 according to this embodiment, the first aspect includes an aspect in which the shorter the time it takes for the subject's gaze to reach the display position of the index, the farther the index is displayed from the reference position. With this configuration, the position of the index to be displayed next can be changed depending on the time it took for the subject's gaze to reach the display position of the index in the previous round, thereby enabling efficient mapping of the visible area.

[Modification]
The display distance of the index from the reference position may be determined based on the previous evaluation result on the extension line of the display position of the index from the reference position. FIG. 13 is a diagram showing an example of the display contents on the display unit in the modified example. Indicators Q21 to Q23 are display examples of indices for evaluating the range of the visual field in the upward direction of the subject. First, in a state in which the index Q21 is displayed at a predetermined distance upward from the reference position P, it is evaluated whether or not the display position of the index Q21 is included in the visible area. If it is evaluated that the display position of the index Q21 is included in the visible area, the next index Q22 is displayed at a position on the extension line between the reference position P and the index Q21 that is farther from the reference position than the index Q21. If it is determined that the display position of the index Q21 is not included in the visible area, the next index Q22 is displayed at a position on the extension line between the reference position P and the index Q21 that is closer to the reference position than the index Q21. By repeating this several times, the range of the visual field in the upward direction of the subject can be determined. Among the display positions of the indices whose display positions are evaluated to be included in the visible area, the display position of the marker that is the furthest away from the reference position is determined to be the visual field range in the upward direction of the subject.

Indicators Q31 to Q33 are examples of indicator display for evaluating the leftward visual field range of the subject. First, in a state where indicator Q31 is displayed at a predetermined distance to the left of reference position P, it is evaluated whether the display position of indicator Q31 is included in the visible area. If it is evaluated that the display position of indicator Q31 is included in the visible area, the next indicator Q32 is displayed at a position on the extension line between reference position P and indicator Q31 that is farther from the reference position than indicator Q31. If it is determined that the display position of indicator Q31 is not included in the visible area, the next indicator Q32 is displayed at a position on the extension line between reference position P and indicator Q31 that is closer to the reference position than indicator Q31. By repeating this several times, the subject's upward visual field range can be determined. The display position of the indicator that is farthest from the reference position among the display positions of the indicators whose display positions are evaluated to be included in the visible area is determined to be the subject's leftward visual field range.

The visual field range is similarly evaluated in the downward and right directions relative to the reference position. The evaluation result of the visual field range may be output as a numerical value, such as the number of degrees in each direction, or the visual field range may be displayed as a diagram using an ellipse or curve. A threshold value for the visual field range may also be set, and the evaluation result output may indicate whether the visual field range is within the acceptable range or not. For example, by using the visual field testing device of the present invention for visual field testing when obtaining a driver's license, etc., an accurate visual field test can be performed in a short time. The visual field range test is not limited to up, down, left, and right, and may also be performed in diagonal directions.

The display directions of the indices relative to the reference position, i.e., the order of the directions for evaluating the visual field range, may be arbitrary, and it is not necessary to display the next indices in the same direction as the display direction of the previous indices. For example, when evaluating the visual field range in the upward and leftward directions, first evaluate whether the display position of index Q21 in FIG. 13 is included in the visible area, then evaluate whether the display position of index Q31 is included in the visible area, and then evaluate whether the display position of index Q22 or index Q23 is included in the visible area based on the evaluation result at the display position of index Q21, and then display whether the display position of index Q32 or index Q33 is included in the visible area based on the evaluation result at the display position of index Q31. When evaluating the visual field range in the up, down, left, and right directions, the evaluation may be performed while changing the evaluation direction as follows: up → down → left → right → up → down → left → right.

The technical scope of the present invention is not limited to the above-described embodiments, and appropriate modifications can be made without departing from the spirit of the present invention.

EB...eyeball, P, P1, P2...reference index, Q, Q1, Q2, Q3, Q4, Q5, Q6, Q7, Q8, Q9, Q10, Q11, Q12, Q13, Q14, Q15...index, 10...display device, 11...display section, 11A...first area, 11B...second area, 11C...third area, 20...eyeball photographing device, 30...control device, 31...display control section, 32...viewpoint detection section, 33...determination section, 34...calculation section, 35...evaluation section, 36...storage section, 100...visual field evaluation device

Claims (6)

A display unit;
a viewpoint detection unit that detects a position of a viewpoint of a subject on the display unit;
a display control unit that sets a position on the display unit where the gaze point of the subject is detected as a reference position and displays an index at a position on the display unit that is distant from the reference position;
an evaluation unit that, when the viewpoint of the subject has moved to the display position of the index, evaluates that the display position of the index is included in a visible area of the subject centered on the reference position, and, when the viewpoint of the subject has not moved to the display position of the index, evaluates that the display position of the index is not included in the visible area;
When the display of the index and the evaluation are performed multiple times in succession, the display control unit, when the display position of the index is evaluated to be included in the visible area in the immediately preceding evaluation, displays the index in a first manner in which the visual recognition difficulty by the subject is higher than in the immediately preceding evaluation, and when the display position of the index is evaluated to be not included in the visible area in the immediately preceding evaluation, displays the index in a second manner in which the visual recognition difficulty is lower than in the immediately preceding evaluation ,
the first aspect is an aspect in which the indicator is displayed at a position where a distance between the reference position and a display position of the indicator is longer than that of the previous time,
The second aspect is an aspect in which the indicator is displayed at a position where the distance between the reference position and the display position of the indicator is shorter than that of the previous time.
Visual field assessment device. A display unit;
a viewpoint detection unit that detects a position of a viewpoint of a subject on the display unit;
a display control unit that sets a position on the display unit where the gaze point of the subject is detected as a reference position and displays an index at a position on the display unit that is distant from the reference position;
an evaluation unit that, when the viewpoint of the subject has moved to the display position of the index, evaluates that the display position of the index is included in a visible area of the subject centered on the reference position, and, when the viewpoint of the subject has not moved to the display position of the index, evaluates that the display position of the index is not included in the visible area;
Equipped with
When the display of the index and the evaluation are performed multiple times in succession, the display control unit, when the display position of the index is evaluated to be included in the visible area in the immediately preceding evaluation, displays the index in a first manner in which the visual recognition difficulty by the subject is higher than in the immediately preceding evaluation, and when the display position of the index is evaluated to be not included in the visible area in the immediately preceding evaluation, displays the index in a second manner in which the visual recognition difficulty is lower than in the immediately preceding evaluation,
the display control unit controls the luminance of the indicator to a plurality of levels and displays the indicator;
The first aspect includes an aspect in which the lower the luminance of the index in the immediately preceding display, the farther the index is displayed from the reference position.
Visual field assessment device. A display unit;
a viewpoint detection unit that detects a position of a viewpoint of a subject on the display unit;
a display control unit that sets a position on the display unit where the gaze point of the subject is detected as a reference position and displays an index at a position on the display unit that is distant from the reference position;
an evaluation unit that, when the viewpoint of the subject has moved to the display position of the index, evaluates that the display position of the index is included in a visible area of the subject centered on the reference position, and, when the viewpoint of the subject has not moved to the display position of the index, evaluates that the display position of the index is not included in the visible area;
Equipped with
When the display of the index and the evaluation are performed multiple times in succession, the display control unit, when the display position of the index is evaluated to be included in the visible area in the immediately preceding evaluation, displays the index in a first manner in which the visual recognition difficulty by the subject is higher than in the immediately preceding evaluation, and when the display position of the index is evaluated to be not included in the visible area in the immediately preceding evaluation, displays the index in a second manner in which the visual recognition difficulty is lower than in the immediately preceding evaluation,
The first aspect includes an aspect in which the shorter the time it takes for the subject's gaze to reach the display position of the index in the immediately preceding test, the farther the index is displayed from the reference position.
Visual field assessment device. The computer
a viewpoint detection step of detecting a position of a viewpoint of a subject on a display unit;
a display control step of displaying an index at a position on the display unit away from the reference position, the position on the display unit where the gaze point of the subject is detected being set as a reference position;
an evaluation step of evaluating, when the viewpoint of the subject has moved to the display position of the index, that the display position of the index is included in a visible area of the subject centered on the reference position, and evaluating, when the viewpoint of the subject has not moved to the display position of the index, that the display position of the index is not included in the visible area;
Run
When the display control step and the evaluation step are executed multiple times in succession, in the display control step, if the display position of the index is evaluated to be included in the visible area in the immediately preceding evaluation, the index is displayed in a first manner in which the visual recognition difficulty by the subject is higher than in the immediately preceding evaluation, and if the display position of the index is evaluated to be not included in the visible area in the immediately preceding evaluation, the index is displayed in a second manner in which the visual recognition difficulty is lower than in the immediately preceding evaluation,
the first aspect is an aspect in which the indicator is displayed at a position where a distance between the reference position and a display position of the indicator is longer than that of the previous time,
The second aspect is an aspect in which the indicator is displayed at a position where the distance between the reference position and the display position of the indicator is shorter than that of the previous time.
Visual field assessment methods. The computer
a viewpoint detection step of detecting a position of a viewpoint of a subject on a display unit;
a display control step of displaying an index at a position on the display unit away from the reference position, the position on the display unit where the gaze point of the subject is detected being set as a reference position;
an evaluation step of evaluating, when the viewpoint of the subject has moved to the display position of the index, that the display position of the index is included in a visible area of the subject centered on the reference position, and evaluating, when the viewpoint of the subject has not moved to the display position of the index, that the display position of the index is not included in the visible area;
Run
When the display control step and the evaluation step are executed multiple times in succession, in the display control step, if the display position of the index is evaluated to be included in the visible area in the immediately preceding evaluation, the index is displayed in a first manner in which the visual recognition difficulty by the subject is higher than in the immediately preceding evaluation, and if the display position of the index is evaluated to be not included in the visible area in the immediately preceding evaluation, the index is displayed in a second manner in which the visual recognition difficulty is lower than in the immediately preceding evaluation,
In the display control step, the luminance of the index is controlled in a plurality of stages and displayed;
The first aspect includes an aspect in which the lower the luminance of the index in the immediately preceding display, the farther the index is displayed from the reference position.
Visual field assessment methods. The computer
a viewpoint detection step of detecting a position of a viewpoint of a subject on a display unit;
a display control step of displaying an index at a position on the display unit away from the reference position, the position on the display unit where the gaze point of the subject is detected being set as a reference position;
an evaluation step of evaluating, when the viewpoint of the subject has moved to the display position of the index, that the display position of the index is included in a visible area of the subject centered on the reference position, and evaluating, when the viewpoint of the subject has not moved to the display position of the index, that the display position of the index is not included in the visible area;
Run
When the display control step and the evaluation step are executed multiple times in succession, in the display control step, if the display position of the index is evaluated to be included in the visible area in the immediately preceding evaluation, the index is displayed in a first manner in which the visual recognition difficulty by the subject is higher than in the immediately preceding evaluation, and if the display position of the index is evaluated to be not included in the visible area in the immediately preceding evaluation, the index is displayed in a second manner in which the visual recognition difficulty is lower than in the immediately preceding evaluation,
The first aspect includes an aspect in which the shorter the time it takes for the subject's gaze to reach the display position of the index in the immediately preceding test, the farther the index is displayed from the reference position.
Visual field assessment methods.

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