Method for measuring behavioral patterns during eye movement, and apparatus for measuring behavioral patterns during eye movement

Abstract

To provide a technique for measuring a behavior pattern when a subject moves his / her line of sight, which is useful information for determining a progressive refractive-power lens more suitable for the subject.SOLUTION: The method for measuring behavior pattern upon visual line movements includes: a step for having visual recognition of a visual target conducted by a subject by displaying the visual target on at least one of a plurality of display units disposed at different distances from the subject wearing a progressive refractive-power lens; and a step for obtaining a subjective response from the subject who has visually recognized the visual target. This method makes the subject experience two or more different visual states and measures a change in the behavior of the subject between the visual states, by repeating the step for having visual recognition conducted and the step for obtaining a subjective response, with respect to a plurality of the visual targets.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a method for measuring a behavior pattern during line-of-sight movement, a method for determining a progressive-power lens, and a device for measuring a behavior pattern during line-of-sight movement.

Background Art

[0002] Various methods have been proposed for designing progressive-power lenses suitable for test subjects. For example, Patent Document 1 discloses a method for determining the visual behavior of a human, which includes the step of recording the movement of the human's head while performing a visual task, and further comprises the steps of recording at least one eye movement of the human while performing the visual task, determining the relative orientation of the eyeball with respect to the head at different time points, and determining the amount of time that the eyeball was held in each orientation.

[0003] Furthermore, Patent Document 2 discloses an ophthalmic lens evaluation method, which includes: a task posing step in which an ophthalmic lens suitability inspection device displays a plurality of visual targets at a plurality of different display positions respectively, poses a predetermined task to a test subject wearing an ophthalmic lens, and causes the test subject to provide an answer to the task for each of the plurality of visual targets; a task evaluation step in which the ophthalmic lens suitability inspection device determines an evaluation score for the task at each of the plurality of display positions, using the correctness of the answer to the task that the test subject made based on the result of visually observing the plurality of visual targets and judging the state thereof; and a lens evaluation step in which the ophthalmic lens suitability inspection device evaluates the suitability of the ophthalmic lens for the test subject using the evaluation score of the task.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

[0005] One embodiment of the present invention aims to provide a technique for measuring the behavioral patterns of a subject's gaze movements, which provide useful information for determining a more suitable progressive power lens for the subject. [Means for solving the problem]

[0006] A first aspect of the present invention is: A step of displaying a visual target on at least one of a plurality of display units positioned at different distances from a subject wearing progressive power lenses, and causing the subject to view the visual target; The process includes obtaining a subjective response from the subject who has visually observed the aforementioned target, This method for measuring eye-tracking behavioral patterns involves repeating the steps of having a subject view multiple visual targets and obtaining a subjective response, thereby allowing the subject to experience two or more different visual states, and measuring the changes in the subject's behavior between these visual states.

[0007] A second aspect of the present invention is: The method for measuring the behavioral pattern during gaze movement described in the first embodiment above includes a change in at least one of the following: the correctness of the subjective response, the response time from the display of the target to obtaining the subjective response, and the movement of the subject's head or eyeballs from the display of the target to obtaining the subjective response.

[0008] A third aspect of the present invention is: The two or more different visual states include near-vision and far-vision, and the method for measuring the behavioral pattern during gaze movement described in the first embodiment above.

[0009] A fourth aspect of the present invention is: The method for measuring eye movement behavior patterns according to the first embodiment is characterized in that, when repeating the step of making the subject see the object and the step of obtaining the subjective response, the plurality of objects are displayed in a certain order so that the subject makes a series of eye movements with respect to discrete viewing distances.

[0010] A fifth aspect of the present invention is: The method for measuring eye movement behavior patterns according to the first embodiment, wherein the steps of making the subject visually perceive the target and obtaining the subjective response involve continuously imaging the subject and measuring the movement of the subject's head or eyeballs from the time the visual target is displayed until the subjective response is obtained.

[0011] A sixth aspect of the present invention is: A step of displaying a visual target on at least one of a plurality of display units positioned at different distances from a subject wearing progressive power lenses, and causing the subject to view the visual target; The process includes obtaining a subjective response from the subject who has visually observed the aforementioned target, By repeating the process of having the subject view multiple visual targets and the process of obtaining the subjective response multiple times, the subject experiences two or more different visual states, and the change in the subject's behavior between the visual states is measured. The method for determining progressive refractive power lenses further comprises the step of selecting a design for a progressive refractive power lens suitable for the subject based on the data of the aforementioned changes in behavior.

[0012] A seventh aspect of the present invention is: Multiple display units are positioned at different distances from a subject wearing progressive lenses and display targets for the subject to view; An input unit for inputting the subjective response of the subject who has visually observed the aforementioned target, A device for measuring behavioral patterns during eye movement, comprising: a measuring unit that causes the subject to experience two or more different visual states by repeatedly displaying the visual target and inputting the subjective response multiple times, and measures the change in the subject's behavior between the visual states.

[0013] An eighth aspect of the present invention is, The apparatus for measuring a behavior pattern during gaze movement according to the seventh aspect above, further comprising an imaging unit that continuously images the subject. Effects of the Invention

[0014] According to one embodiment of the present invention, it is possible to measure the behavior pattern of a subject during gaze movement, which serves as useful information for determining a progressive power lens more suitable for the subject. Brief Description of the Drawings

[0015] [Figure 1] Figure 1 is a flowchart showing an example of the method for measuring a behavior pattern during gaze movement and the method for determining a progressive power lens according to the first embodiment of the present invention. [Figure 2] Figure 2 is a schematic diagram for explaining the gaze movement task according to the first embodiment of the present invention. [Figure 3] Figure 3(a) and Figure 3(b) are schematic diagrams showing an example of a display unit on which a visual target is displayed according to the first embodiment of the present invention. [Figure 4] Figure 4 is a schematic diagram for explaining the display position of the visual target 30 on the display unit according to the first embodiment of the present invention. [Figure 5] Figure 5 is a diagram plotting the measured behavior pattern data (response time and posture stability) during gaze movement of each subject according to the example of the present invention. [Figure 6] Figure 6 is a diagram plotting the measured behavior pattern data (asymmetry of response time) during gaze movement of each subject according to the example of the present invention. Modes for Carrying Out the Invention

[0016] <Findings Obtained by the Inventor> First, let me explain the findings the inventors have gained. As the individual design of progressive lenses suitable for each subject progresses, methods have been proposed to acquire the relationship between the subject's eye movements and head movements, as well as changes in viewing distance, while the subject is performing a specific task (e.g., reading or using a tablet), and to reflect these findings in the optical design of the progressive lens. The usable range of a progressive lens when performing such a specific task is relatively limited compared to the entire lens, considering the movement of the line of sight and changes in viewing distance.

[0017] In contrast, it was found that the most common situations in which subjects felt dissatisfied with using progressive lenses (for example, difficulty focusing) were when raising their heads to look at distant objects or when shifting their gaze and then returning to it (for example, in real life, when switching from reading to watching television and then returning to reading). Thus, in order to reproduce the situation of switching between viewing (focusing on) objects at different viewing distances and measure the behavioral patterns of subjects during eye movement, it is necessary to change the viewing distance and the presentation position of the target more dynamically, rather than eye movement that follows the object (quasi-static visual behavior), and to significantly change the range of use of progressive lenses. At the same time, considering that the movement of changing the viewing distance and then returning to the same viewing distance is common, it is also important to have subjects experience a series of movements in order to reproduce the situation of wearing progressive lenses in real life, such as shifting their gaze from a certain visual object (hereinafter referred to as "visual state") to another object, thereby ending that visual state, and then returning to the same visual state.

[0018] The inventors diligently considered the problems described above. As a result, they found a method for measuring behavioral patterns during eye movement, which includes the steps of displaying a target on at least one of several display units placed at different distances from a subject wearing progressive lenses, having the subject view the target, and obtaining a subjective response from the subject who has viewed the target. By repeating the steps of having the subject view the target and obtaining a subjective response for multiple targets, the subject experiences two or more different visual states, and the change in the subject's behavior between the visual states is measured. In this case, since the characteristics of the behavioral pattern may appear in the direction of change when changing to different visual states, it is also useful to measure the case when the direction of change is reversed.

[0019] Specifically, by using different lens regions, such as the distance and near vision areas of a progressive power lens, subjects repeatedly experience changes in their visual state. The accuracy of reading targets after the change in visual state, changes in response time, and changes in the subject's head and eye movements are measured to quantify the subject's ability to refocus and their proficiency in using progressive power lenses. It is also possible to qualitatively capture changes in the subject's behavior between visual states and classify them as individual subject attributes. The data on the subject's behavioral patterns during eye movement measured in this way provides useful information for determining a more suitable progressive power lens for the subject.

[0020] [Details of the Embodiments of the Invention] Next, one embodiment of the present invention will be described below with reference to the drawings. However, the present invention is not limited to these examples and is intended to include all modifications within the meaning and scope equivalent to the claims, as shown in the claims.

[0021] <First Embodiment of the Invention> (1) Method for measuring behavioral patterns during eye movement, and method for determining progressive lenses. First, the method for measuring the behavioral pattern during eye movement and the method for determining progressive power lenses according to this embodiment will be described. Figure 1 is a flowchart showing an example of the method for measuring the behavioral pattern during eye movement and the method for determining progressive power lenses according to this embodiment. As shown in Figure 1, the method for measuring the behavioral pattern during eye movement according to this embodiment includes, for example, a target display step S101 and a subjective response acquisition step S102. By repeating the above two steps multiple times, the subject is made to experience two or more different visual states, and the changes in the subject's behavior between visual states are measured multiple times. Hereinafter, the task of repeating the target display step S101 and the subjective response acquisition step S102 multiple times will be referred to as the "eye movement task" in this specification. When applying the present invention as a method for determining progressive power lenses, the design selection step S103 can be performed after measuring the subject's behavioral pattern during eye movement using the eye movement task.

[0022] Figure 2 is a schematic diagram illustrating the eye-tracking task of this embodiment. As shown in Figure 2, multiple display units (in this embodiment, a first display unit 20 and a second display unit 21) are arranged at different distances from the subject 10 wearing progressive lenses. The first display unit 20 is, for example, a display terminal such as a tablet, and is a display unit for displaying a target that assumes a distant viewing state (a state in which the distance portion of the progressive lenses is being used). The first display unit 20 is positioned such that, for example, the subject 10's line of sight when looking straight ahead at a distance (for example, viewing distance dL = 3m) is at the center of the screen. The second display unit 21 is, for example, a display terminal such as a smartphone, and is a display unit for displaying a target that assumes a near viewing state (a state in which the near portion of the progressive lenses is being used). The second display unit 21 is positioned such that, for example, the subject 10's line of sight when looking near downwards (for example, viewing distance dS = 40cm, downwards at 30 degrees) is at the center of the screen.

[0023] The difference in viewing distance dM (=dL-dS) between the first display unit 20 and the second display unit 21 is preferably greater than the depth of field, which is the range in which the subject 10 perceives focus as sharp or does not perceive blurring even if the position of the object and the position of focus adjustment do not coincide when the subject 10 exercises a certain degree of accommodation to focus on the object. In other words, it is preferable that the multiple display units used in the eye movement task are arranged at different distances greater than the depth of field. Here, the depth of field depends on the effects of aberrations and pupil diameter, as well as the viewing angle of the object, but according to model eye calculations that ignore aberrations, the depth of field for an eye with a pupil diameter of 4 mm and a decimal visual acuity of 1.0 is said to be about 0.15 D (see "Optical Vision Expert: Optics and Eyeglasses" (Igaku-Shoin, 2018)). As a result, it becomes impossible for the subject 10 to focus on multiple display units (in this embodiment, the first display unit 20 and the second display unit 21) simultaneously, requiring more dynamic eye movements and making it easier to measure the behavioral patterns during eye movements.

[0024] (Visual target display process S101, subjective response acquisition process S102) The target display step S101 is a step in which a target is displayed on at least one of the multiple display units (in this embodiment, the first display unit 20 and the second display unit 21) (in this embodiment, either one) to allow the subject 10 to view the target. Figures 3(a) and 3(b) are schematic diagrams showing examples of display units with a target displayed. Figure 3(a) shows an example in which the target 30 is displayed on the first display unit 20 and not on the second display unit 21. Figure 3(b) shows an example in which the target 30 is displayed on the second display unit 21 and not on the first display unit 20. In Figures 3(a) and 3(b), the arrows extending from the subject 10 represent the direction of the subject 10's gaze. As shown in Figures 3(a) and 3(b), in the target display step S101 of this embodiment, the target 30 is displayed on only one of the display units, making it easier for the subject 10 to recognize the target 30 that they should be viewing. Furthermore, by changing the display unit on which the target 30 is displayed, the subject 10 can be made to experience different visual states. The target 30 displayed on the display unit is not particularly limited as long as it can be clearly viewed when the subject 10 focuses on it. In this embodiment, as shown in Figures 3(a) and 3(b), a Landolt ring (equivalent to a visual acuity of 0.7) is used as the target 30.

[0025] The subjective response acquisition step S102 is a step in which subjective responses are obtained from the subject 10 who has viewed the visual target 30 displayed in the visual target display step S101. In this embodiment, the subject 10 answers the direction of the gap in the Landolt ring using the input unit 40. As shown in Figures 3(a) and 3(b), the input unit 40 is, for example, a software key displayed on a smartphone or the like, and in this embodiment, the second display unit 21 also serves the role of the input unit 40.

[0026] In the subjective response acquisition step S102, once a subjective response from the subject 10 is obtained, the target display step S101 is performed again. Specifically, for example, if the target 30 was displayed on the first display unit 20 in the previous target display step S101, the target 30 on the first display unit 20 is erased and the target 30 is displayed on the second display unit 21, as shown in Figure 3(b). Alternatively, if the target 30 was displayed on the second display unit 21 in the previous target display step S101, the target 30 on the second display unit 21 is erased and the target 30 is displayed on the first display unit 20, as shown in Figure 3(a). Thus, in the target display step S101, it is preferable to have the subject 10 alternately view the target 30 displayed on the first display unit 20 and the target 30 displayed on the second display unit 21 (i.e., alternate between near and far viewing). As a result, subject 10 will perform eye movements across discrete viewing distances, such as from far to near, or from near to far, leading to more dynamic eye movements and making it easier to measure behavioral patterns during eye movements.

[0027] As described above, by repeating the target display step S101 and the subjective response acquisition step S102 multiple times, the subject 10 experiences two or more different visual states (in this embodiment, a near-vision state and a far-vision state), and by measuring the changes in the subject 10's behavior between visual states multiple times, it becomes possible to measure the subject 10's behavioral patterns during eye movement. Changes in the subject 10's behavior include, for example, changes in at least one of the following: the correctness of the subject 10's subjective response, the response time from displaying the target 30 to obtaining a subjective response, and the movement of the subject 10's head or eyeballs from displaying the target 30 to obtaining a subjective response, preferably including all of these changes. Specifically, for example, if there are many incorrect subjective responses as a behavioral pattern during eye movement, it may be determined that the subject 10 has a low ability to refocus or a low level of proficiency in using progressive lenses. For example, if there is a significant difference in the response time when shifting gaze from near to far and when shifting gaze from far to near, it may be determined that subject 10 has asymmetry in response time. Also, if there is a lot of unnecessary head movement and eye movement in the behavioral pattern of gaze shifting, it may be determined that subject 10 has low postural stability. All of these behavioral patterns during gaze shifting suggest that the design and fitting method of the progressive power lenses are not as intended by the designer. On the other hand, if, for example, the behavioral pattern during gaze shifting involves smooth head movement and gaze movement (i.e., high postural stability), short response times, and no subjective errors in response, it may be determined that subject 10 has high refocusing ability and proficiency in using progressive power lenses. In this case, it can be inferred that the behavioral pattern during gaze shifting is the desirable one intended by the designer. By measuring multiple behavioral changes (parameters) as described above multiple times, it becomes possible to measure the behavioral pattern during gaze shifting from multiple angles.

[0028] In the target display step S101 and the subjective response acquisition step S102, it is preferable to continuously image the face of the subject 10 and measure the movement of the subject's head or eyeballs from the time the target 30 is displayed until a subjective response is obtained. In this embodiment, as shown in Figures 3(a) and 3(b), the face of the subject 10 is continuously imaged by an imaging unit 50 (for example, a smartphone camera) provided on the second display unit 21. In other words, in this embodiment, the second display unit 21 also serves as the imaging unit 50. By applying known techniques such as image recognition to the images captured by the imaging unit 50, it is possible to acquire head movement data, gaze movement data, interpupillary distance data, etc. of the subject 10, making it possible to measure the behavioral pattern during gaze movement from a more multifaceted perspective.

[0029] Figure 4 is a schematic diagram illustrating the display position of the target 30 on the display unit. In Figure 4, the target 30 is displayed at display position P7 (lower left of the screen), but in the target display step S101, it is preferable to randomize the display position of the target 30 within the screen of the display unit (for example, to any of display positions P1 to P9). If the display position of the target 30 is the same each time (for example, always at display position P5 in the center of the screen), the subject 10 may anticipate the display position of the target 30 and move their gaze before the target 30 is displayed, making it difficult to accurately measure the behavioral pattern during gaze movement. In contrast, by randomizing the display position of the target 30, it becomes more difficult for the subject 10 to anticipate the display position of the target 30, making it easier to accurately measure the behavioral pattern during gaze movement. Furthermore, it is preferable that the change in the display position of the target 30 within the screen of the display unit be such that the viewing distance remains almost unchanged (for example, a change of less than 0.15 to 0.2D in depth of field).

[0030] By performing the eye-shifting task described above, it is possible to measure the behavioral patterns of subject 10 during eye-shifting, which provides useful information for determining a more suitable progressive lens for subject 10.

[0031] (Design selection process S103) The design selection process S103 is a process of selecting a progressive lens design suitable for subject 10 based on data of the subject's behavioral patterns during eye movement measured by an eye movement task (data of changes in subject 10's behavior). Specifically, for example, the data of the subject's behavioral patterns during eye movement when wearing a progressive lens of design A may be compared with the data of the subject's behavioral patterns when wearing a progressive lens of design B, and the design that is judged to be more desirable in terms of the behavioral patterns during eye movement as intended by the designer may be selected. Alternatively, for example, for subject 10 whose behavioral patterns during eye movement were not as intended by the designer, an improved design that facilitates refocusing, which involves a trade-off with quality (image quality) on the principal meridian, may be selected, and for subject 10 whose behavioral patterns during eye movement were as desirable as intended by the designer, a design that prioritizes quality on the principal meridian may be selected. In addition, in the design selection process S103, for example, a lens with a design suitable for the subject may be selected from several pre-prepared customized lenses.

[0032] By applying the methods described above to multiple subjects, it is possible to design progressive lenses that are suitable for the individual needs of each subject.

[0033] (2) Device for measuring behavioral patterns during eye movement The present invention can also be applied as a device for measuring the behavioral patterns of a subject 10 during eye movement. The device for measuring the behavioral patterns of an eye movement in this embodiment includes, for example, a plurality of display units (e.g., a first display unit 20 and a second display unit 21) positioned at different distances from the subject 10 wearing progressive lenses and displaying a target 30 for the subject 10 to view; an input unit 40 for inputting the subject 10's subjective response to view the target 30; and a measurement unit that allows the subject 10 to experience two or more different visual states (e.g., near vision and far vision) by repeating the display of the target 30 and the input of the subjective response multiple times, and measures the change in the subject 10's behavior between the visual states multiple times. The measurement unit is, for example, an information processing device capable of processing and storing data, and the first display unit 20 or the second display unit 21 may also serve as the measurement unit. Furthermore, it is preferable that the device for measuring the behavioral patterns of an eye movement further includes an imaging unit 50 that continuously images the face of the subject 10.

[0034] <Other embodiments of the present invention> Although embodiments of the present invention have been specifically described above, the present invention is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention.

[0035] For example, in the embodiment described above, the case in which the first display unit 20 and the second display unit 21 are arranged as multiple display units used in the eye-tracking task was explained, but three or more display units may be arranged. Also, the display units may be arranged in positions other than in front of the subject 10, such as to the side. Furthermore, it is not necessarily required to use multiple display devices in order to arrange multiple display units; for example, a part of one display device may be designated as the first display unit 20 and another part as the second display unit 21.

[0036] Furthermore, in the above embodiment, for example, as shown in Figure 2, the case in which the first display unit 20 is placed far in front of the subject 10 and the second display unit 21 is placed near and below (30 degrees below) the subject 10 has been described. However, the angle (viewing angle) at which the multiple display units are placed is not limited to the above embodiment. Nevertheless, it is preferable that the multiple display units be placed so that they do not overlap from the perspective of the subject 10, and that the viewing angles from the subject 10 are all different. Also, from the viewpoint of making it easier for the subject 10 to see the target 30 in a natural posture, it is preferable that, as in the above embodiment, the display unit corresponding to distant viewing (first display unit 20) is placed in front of the subject 10, and the display unit corresponding to near viewing (second display unit 21) is placed below the subject 10.

[0037] Furthermore, although the above-described embodiment described the case in which a Landolt ring equivalent to a visual acuity of 0.7 is used as the target 30, the form of the target 30 is not limited to the above-described embodiment. Specifically, for example, it may be an arrow or letters, or a simple figure (circle or polygon). Regarding the size of the target 30, it is preferable to present it after adjusting it according to the distance so that the visual angle does not differ greatly depending on the viewing distance. From the viewpoint of effectively measuring the behavioral pattern during eye movement, which is the objective of the present invention, it is preferable to make it large enough that it cannot be seen unless the eyes are properly directed at it, and to make it approximately equivalent to a visual acuity of 0.7 to 1.0.

[0038] Furthermore, in the above-described embodiment, for example, the case in which the second display unit 21 is used as the input unit 40 and subjective responses from the subject 10 are obtained using software keys displayed on the second display unit 21 was explained, but the form of the input unit 40 is not limited to the above-described embodiment. For example, an input device equipped with a lever or a directional pad, or a voice input device that can obtain subjective responses from the subject 10's voice, may be used as the input unit 40, or the configuration may be such that a measurement assistant can manually input the subject 10's subjective responses. In addition, from the viewpoint of preventing the subject 10's gaze from moving away from the target 30, it is preferable that the input unit 40 allows subject 10 to input subjective responses while keeping their gaze fixed on the target 30.

[0039] Furthermore, in the above-described embodiment, for example, a camera provided on the second display unit 21 is used as the imaging unit 50 to continuously image the face of the subject 10, thereby measuring the movement of the subject 10's head or eyeballs from the time the visual target 30 is displayed until a subjective response is obtained. However, the manner in which the movement of the subject 10's head or eyeballs is measured is not limited to the above-described embodiment. For example, the distance between the second display unit 21 and the subject 10's head, or the interpupillary distance of the subject 10, may be measured using LIDAR (Laser Imaging Detection and Ranging) provided in a smartphone or the like.

[0040] Furthermore, in the embodiment described above, for example, the case in which the subject 10 alternately views the target 30 displayed on the first display unit 20 and the target 30 displayed on the second display unit 21 (i.e., alternates between near and far viewing), is explained. However, in the target display step S101, it is not always necessary to alternate between near and far viewing. For example, in the target display step S101, which is performed multiple times, if the subject occasionally shifts their gaze from near to near, or from far to far, it becomes more difficult for the subject 10 to predict the display position of the target 30, making it easier to accurately measure their behavioral patterns during gaze movement.

[0041] Furthermore, in the embodiment described above, the case in which the visual target 30 is displayed on only one of the multiple display units (first display unit 20 and second display unit 21) in the visual target display step S101 was explained. However, in the visual target display step S101, it is sufficient to display the visual target 30 on at least one of the multiple display units, and the visual target 30 may be displayed on each of the multiple display units simultaneously. Specifically, for example, the visual target 30 may be displayed on both the first display unit 20 and the second display unit 21, and the subject 10 may be made to view the visual target 30 displayed in a brightly lit position, or the subject 10 may be made to view the visual target 30 displayed in a position pointed to by a pointer or the like. Even in such cases, the subject 10 can be made to experience two or more different visual states, making it possible to measure the behavioral patterns during eye movement. [Examples]

[0042] Next, embodiments of the present invention will be described. These embodiments are examples of the present invention, and the present invention is not limited to these embodiments.

[0043] In this example, 34 subjects performed an eye-tracking task under the following conditions. As shown in Figure 2, the first display unit 20 (tablet) was placed directly in front of the subject 10 (viewing distance dL = 3 m), and the second display unit 21 (smartphone) was placed 30 degrees below the subject 10 (viewing distance dS = 40 cm). A Landolt ring equivalent to a visual acuity of 0.7 was used as the visual target 30. The visual target 30 was displayed alternately on the first display unit 20 and the second display unit 21 a total of 30 times, and the subject 10 was asked to indicate the direction of the gap in the Landolt ring. The response (subjective response) was given using a software key (input unit 40) displayed on the second display unit 21. While the eye-tracking task was being performed, the camera (imaging unit 50) provided on the second display unit 21 continuously captured images (30 times per second), and the movement of the subject's head (specifically, the change in the distance between the second display unit 21 and the subject's face over time) was measured by image recognition.

[0044] (1) Response time and postural stability The data on each subject's behavioral patterns during eye movement (response time and postural stability), measured by the eye movement task described above, were plotted and organized in Figure 5. In Figure 5, the horizontal axis shows the average response time when switching from far-field to near-field gaze (average response time), and the vertical axis shows postural stability. In this embodiment, postural stability is an index of the subject's large postural changes synchronized with the response, calculated by extracting the low-frequency component (10 Hz or less) from the time-dependent change in the distance between the second display unit and the subject's face, and then taking the root mean square (RMS) of the fluctuation range. A smaller value indicates greater postural stability.

[0045] In the results shown in Figure 5, the average average response time for all subjects was 2.4 seconds, and the average postural stability was 6.5 mm. Therefore, subjects with an average response time of less than 2.4 seconds and postural stability of 6.5 mm or more were classified as Group A (upper left of Figure 5), subjects with an average response time of 2.4 seconds or more and postural stability of 6.5 mm or more were classified as Group B (upper right of Figure 5), subjects with an average response time of less than 2.4 seconds and postural stability of less than 6.5 mm were classified as Group C (lower left of Figure 5), and subjects with an average response time of 2.4 seconds or more and postural stability of less than 6.5 mm were classified as Group D (lower right of Figure 5). In other words, subjects were classified as follows: Group A had a fast response but unstable posture; Group B had a slow response and unstable posture; Group C had a fast response and stable posture; and Group D had a slow response but stable posture.

[0046] For subjects in group C, who were considered to have a high level of proficiency in using progressive lenses, a design based on the progressive lens design currently worn by the subject, or a design prioritizing quality along the principal meridian, was selected. For subjects in group B, who were considered to have a low level of proficiency in using progressive lenses, a lens design for initial use, or a design with a shorter progressive zone length to minimize eye movement, was selected. For example, subjects in group B could also be provided with lectures on how to use their eyes while wearing progressive lenses. For subjects in group D, who exhibited less postural sway and a longer response time when switching to near vision, a design that tolerated intermediate distortion to widen the clear vision area in the near vision area (e.g., a hard design) was selected.

[0047] In this embodiment, data on the behavioral patterns during eye movement were used to classify the subjects. However, it is also possible to determine which progressive lens design is more suitable by, for example, having the same subject wear multiple progressive lenses and comparing the data on their behavioral patterns during eye movement. Specifically, by comparing designs with longer and shorter progressive zones, hard and soft designs, and distance-focused and near-focused designs, it is possible to propose a design that is more suitable for the subject by selecting the lens design that resulted in a behavioral pattern during eye movement that was more desirable as intended by the designer (for example, a shorter response time and greater postural stability).

[0048] In this embodiment, the design of a progressive lens suitable for the subject was selected based on average response time and postural stability data. However, it is also possible to select the design based on, for example, the accuracy rate of subjective responses or the variability (symmetry) of response times.

[0049] (2) Asymmetry of response time Furthermore, data on the behavioral patterns of each subject during eye movement (asymmetry of response time), measured by the eye movement task described above, were plotted and organized in Figure 6. In Figure 6, the horizontal axis shows the average response time when switching from far vision to near vision (FN time), and the vertical axis shows the average response time when switching from near vision to far vision (NF time). Normally, there is no extreme difference in the time taken for each eye movement, but in some cases, asymmetry in response time may appear. In such cases, it was determined that the subject had room to use progressive lenses more comfortably.

[0050] In the lower right of Figure 6, the subjects in the shaded area take longer to shift their gaze from near to far than they do to shift their gaze from near to far. This suggests that their near-vision gaze path and intermediate gaze path are unstable, or that they are unfamiliar with how to use their gaze with progressive lenses, resulting in longer refocusing times. For these subjects, a design with a wider horizontal power stability range for near vision was chosen. This is expected to make refocusing easier because the required accommodative force remains constant even with small horizontal gaze movements.

[0051] In summary, we confirmed that by measuring the behavioral patterns of subjects during eye movement using an eye-shifting task, it is possible to select (determine) a more suitable progressive power lens design for each subject based on the measured data of these behavioral patterns. [Explanation of symbols]

[0052] 10 subjects 20 1st display section 21 2nd display section 30 optotype 40 Input section 50 Imaging Unit S101 Visual target display process S102 Awareness response acquisition process S103 Design Selection Process

Claims

1. A step of displaying a visual target on at least one of a plurality of display units positioned at different distances from a subject wearing progressive power lenses, and causing the subject to view the visual target; The process includes obtaining a subjective response from the subject who has visually observed the aforementioned target, A method for measuring behavioral patterns during eye movement, comprising repeating the steps of having a subject view multiple visual targets and obtaining a subjective response, thereby causing the subject to experience two or more different visual states, and measuring the change in the subject's behavior between the visual states.

2. The method for measuring a behavioral pattern during gaze movement according to claim 1, wherein the change in behavior includes a change in at least one of the following: the correctness of the subjective response, the response time from the display of the target to obtaining the subjective response, and the movement of the subject's head or eyeballs from the display of the target to obtaining the subjective response.

3. The method for measuring a behavioral pattern during eye movement according to claim 1, wherein the two or more different visual states include a near-vision state and a far-vision state.

4. The method for measuring eye movement behavior patterns according to claim 1, wherein when the step of making the subject see the objects and the step of obtaining the subjective response are repeated, the plurality of visual targets are repeatedly displayed in a certain order so that the subject makes a series of eye movements with respect to discrete viewing distances.

5. The method for measuring a behavioral pattern during gaze movement according to claim 1, wherein in the step of making the subject visible and the step of obtaining the subjective response, the subject is continuously imaged and the movement of the subject's head or eyeballs is measured from the time the visual target is displayed until the subjective response is obtained.

6. Multiple display units are positioned at different distances from a subject wearing progressive lenses and display targets for the subject to view; An input unit for inputting the subjective response of the subject who has visually observed the aforementioned target, A device for measuring eye movement behavior patterns, comprising: a measuring unit that causes the subject to experience two or more different visual states by repeatedly displaying the visual target and inputting the subjective response, and measures the change in the subject's behavior between the visual states.

7. The apparatus for measuring eye movement behavior patterns according to claim 6, further comprising an imaging unit for continuously imaging the subject.

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