Binocular vision function measurement method, binocular vision function measurement program, spectacle lens design method, spectacle lens manufacturing method, and binocular vision function measurement system

Abstract

A binocular vision function measurement method is provided, comprising: a visual mark presenting step, in which, on a single movable display screen, a right-eye image for the subject to be visually confirmed by the right eye and a left-eye image for the subject to be visually confirmed by the left eye; a presentation control step, in which the presentation positions of the right-eye image and the left-eye image are relatively changed; a timing detection step, in which the timing at which the subject cannot fuse the right-eye image with the left-eye image when the presentation position is changed; and a parameter value calculation step, in which a prescribed parameter value for the binocular vision function of the subject is calculated based on the relative positional relationship between the right-eye image and the left-eye image when the timing is detected.

Description

Technical Field

[0001] The present invention relates to a binocular vision function measuring method, a binocular vision function measuring program, a spectacle lens design method, a spectacle lens manufacturing method and a binocular vision function measuring system. Background Art

[0002] When performing binocular vision tests on eyeglass wearers, for example, the convergence and divergence ranges may be measured. There are individual differences in the convergence and divergence ranges, and measuring them is very important in the design of eyeglass lenses and in understanding the function of the eyes when looking at near objects.

[0003] Patent document 1 discloses that, for binocular vision functions represented by convergence and divergence ranges, for example, left and right parallax images are presented using a fixed three-dimensional corresponding video monitor, the respective presentation positions are moved relatively, and the timing at which they cannot be fused is detected to measure the binocular vision function.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2012-95693 Summary of the invention

[0007] Problems to be solved by the invention

[0008] In the binocular vision function measurement method disclosed in Patent Document 1, a fixed three-dimensional corresponding video monitor is used to measure the binocular vision function. Therefore, the position of the head of the person being measured is not fixed relative to the left and right parallax images, and there is a concern that errors may occur in the median plane depending on the direction of the head during the measurement. In addition, since the fixed three-dimensional corresponding video monitor is placed in the actual environment, in addition to the displayed parallax information, the person being measured also obtains information (actual space information) about the depth and sense of distance from the outside world, so there is a possibility of convergence and divergence in the form of linkage with the usual adjustment. Furthermore, since the fixed three-dimensional corresponding video monitor is used, the required system structure becomes huge, so it cannot be said that the binocular vision function can be measured simply.

[0009] An object of the present invention is to provide a technique capable of measuring the binocular vision function of a subject with high accuracy and very simply.

[0010] Means for solving problems

[0011] The present invention is proposed to achieve the above-mentioned object.

[0012] A first aspect of the present invention is a binocular vision function measurement method, comprising:

[0013] a step of presenting an optotype, presenting, on a single movable display screen, to the subject an image for the right eye to be visually recognized by the subject's right eye and an image for the left eye to be visually recognized by the subject's left eye;

[0014] A presentation control step of relatively changing presentation positions of the right-eye image and the left-eye image;

[0015] a timing detection step of detecting a timing at which the subject cannot fuse the right-eye image with the left-eye image when the presentation position is changed; and

[0016] The parameter value calculation step calculates a predetermined parameter value for the binocular vision function of the subject based on the relative positional relationship between the right-eye image and the left-eye image when the timing is detected.

[0017] A second aspect of the present invention is the binocular vision function measurement method according to the first aspect,

[0018] The right-eye image and the left-eye image are presented using a display screen of a portable information terminal as the movable display screen.

[0019] A third aspect of the present invention is the binocular vision function measurement method according to the first or second aspect,

[0020] The predetermined parameter value is a value that specifies the convergence range of the person being measured.

[0021] A fourth aspect of the present invention is the binocular vision function measurement method according to any one of the first to third aspects,

[0022] have:

[0023] The tracking ability determination step determines the degree of tracking ability of the subject's eye for position changes of the presented image by changing the speed at which the relative positions of the right-eye image and the left-eye image change to obtain a plurality of the predetermined parameter values.

[0024] A fifth aspect of the present invention is the binocular vision function measurement method according to any one of the first to fourth aspects,

[0025] The right-eye image and the left-eye image are composed of graphics having the same shape and size.

[0026] A sixth aspect of the present invention is the binocular vision function measurement method according to any one of the first to fifth aspects,

[0027] have:

[0028] The viewing distance setting step sets the viewing distance of the subject with respect to the right-eye image and the left-eye image.

[0029] A seventh aspect of the present invention,

[0030] The present invention is a binocular vision function measuring program for causing a computer to execute the binocular vision function measuring method according to any one of the first to sixth aspects.

[0031] An eighth aspect of the present invention is a method for designing eyeglass lenses, comprising:

[0032] A step of measuring the binocular vision function of a subject using the binocular vision function measuring method according to any one of the first to sixth aspects; and

[0033] A step of determining optical design values ​​of eyeglass lenses based on the measurement results of the binocular vision function.

[0034] A ninth aspect of the present invention is a method for manufacturing a spectacle lens, comprising:

[0035] A step of designing a spectacle lens using the spectacle lens design method described in the eighth aspect; and

[0036] The step of manufacturing the eyeglass lens according to the design result of the eyeglass lens.

[0037] A tenth aspect of the present invention is a binocular vision function measurement system comprising:

[0038] an optotype presenting unit that displays, on a single movable display screen, a right-eye image to be visually recognized by the right eye of the subject and a left-eye image to be visually recognized by the left eye of the subject;

[0039] a presentation control unit that relatively changes presentation positions of the right-eye image and the left-eye image;

[0040] a timing detection unit that detects a timing at which the subject cannot fuse the right-eye image with the left-eye image when the presentation position changes; and

[0041] The parameter value calculation unit calculates a predetermined parameter value for the binocular vision function of the subject based on a relative positional relationship between the right-eye image and the left-eye image at the time when the timing is detected.

[0042] According to an eleventh aspect of the present invention, in the binocular vision function measuring system according to the tenth aspect,

[0043] The optotype presenting unit is configured to display the right-eye image and the left-eye image using a display screen of the portable information terminal as the movable display screen.

[0044] Effects of the Invention

[0045] According to the present invention, the binocular vision function of a subject can be measured with high accuracy and very easily. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 This is a block diagram showing the configuration of a spectacle lens manufacturing system for realizing a spectacle lens manufacturing method according to an embodiment of the present invention.

[0047] Figure 2 It is a diagram schematically showing a binocular vision function measurement system according to an embodiment of the present invention.

[0048] Figure 3 : is a block diagram showing the configuration of a binocular vision function measurement system according to an embodiment of the present invention.

[0049] Figure 4 This is a diagram showing a flowchart of processing executed in the convergence range measurement mode of the binocular vision function measurement program according to the embodiment of the present invention.

[0050] Figure 5 This is a transition diagram of an image displayed on the display screen during execution of the convergence range measurement mode in the embodiment of the present invention.

[0051] Figure 6 This is a diagram showing a flowchart of a modification of the process executed in the convergence range measurement mode of the binocular vision function measurement program according to the embodiment of the present invention.

[0052] Figure 7 This is a diagram showing a flowchart of processing executed in the left-right eye vertical divergence allowable value measurement mode of the binocular vision function measurement program according to the embodiment of the present invention.

[0053] Figure 8 This is a transition diagram of an image displayed on the display screen during execution of the left-right eye vertical divergence allowable value measurement mode according to the embodiment of the present invention.

[0054] Fig. 9 This is a diagram showing a flowchart of processing executed in the first unequal magnification allowable value measurement mode of the binocular vision function measurement program according to the embodiment of the present invention.

[0055] Fig.10 This is a transition diagram of an image displayed on the display screen during execution of the first unequal magnification allowable value measurement mode according to the embodiment of the present invention.

[0056] Fig.11This is a diagram showing a flowchart of processing executed in the second unequal magnification allowable value measurement mode of the binocular vision function measurement program according to the embodiment of the present invention.

[0057] Fig.12 This is a transition diagram of an image displayed on the display screen during execution of the second unequal magnification allowable value measurement mode in the embodiment of the present invention.

[0058] Fig.13 This is a diagram for explaining Listing's law.

[0059] Fig.14 This is a diagram for explaining the line of sight directions of the left and right eyes in the case of binocular vision.

[0060] Fig.15 This is a diagram showing a flowchart of processing executed in the left-right eye rotational parallax allowable value measurement mode of the binocular vision function measurement program according to the embodiment of the present invention.

[0061] Fig.16 This is a transition diagram of an image displayed on the display screen during execution of the left-right eye rotational parallax allowable value measurement mode according to the embodiment of the present invention.

[0062] Fig.17 This is a transition map of an image in the first composite measurement mode.

[0063] Fig.18 This is a transition map of an image in the second composite measurement mode.

[0064] Fig.19 This is a transition map of an image in the third composite measurement mode.

[0065] Fig. 20 This is a transition diagram of an image in the measurement mode taking side views into consideration. DETAILED DESCRIPTION

[0066] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0067] <Overview of this embodiment>

[0068] First, the outline of this embodiment will be described.

[0069] In this embodiment, a pair of images with parallax are presented to the left and right eyes of the subject respectively on a single display screen (hereinafter also referred to as a "portable display screen") of a portable information terminal, and the binocular vision function of the subject is measured by judging whether fusion (same vision) occurs when the given parallax is changed. The binocular vision function is measured by calculating a predetermined parameter value for the binocular vision function.

[0070] As a prescribed parameter value, a value of the convergence range of the person being measured is exemplified. The "convergence range" here means the difference in angle between the convergence limit and the divergence limit. In addition, the difference in angle can also be expressed in terms of prism power. In the following description, the case of measuring the convergence range is mainly used as an example, but the prescribed parameter value is not limited to the value of the convergence range, and can also be other parameter values ​​such as the left and right eye upper and lower divergence allowable value, the first unequal magnification allowable value, the second unequal magnification allowable value, the left and right eye rotational parallax allowable value, etc., which will be described later.

[0071] In this embodiment, when measuring binocular vision function, the movable display screen in the portable information terminal is placed in front of the eyes of the subject to present parallax images to the subject. Therefore, parallax images can be presented very simply.

[0072] Furthermore, when the movable display screen is placed in front of the subject's eyes, if the area around the movable display screen is shielded, the parallax image can be presented to the subject in a space cut off from the real space information. That is, the parallax image is presented in front of the subject's eyes in a state where it is shielded from the outside world, so that the subject does not obtain information (real space information) about the sense of depth and perspective from the outside world except for the presented parallax image.

[0073] Furthermore, by keeping the movable display screen in front of the subject's eyes, the parallax image can be positioned at the correct position regardless of the direction of the subject's face.

[0074] Furthermore, if the viewing distance (physical distance between the image and the person viewing the image) for the parallax image is also kept constant, the binocular vision function can be measured while keeping the accommodation function (focusing function) of the subject's eyes constant.

[0075] Thus, according to this embodiment, by placing the movable display screen in front of the eyes of the person being measured, it is possible to perform multiple measurements in the same measurement environment without paying attention to the body posture or position of the person being measured. In addition, by using the movable display screen in the portable information terminal to present only a pair of parallax images, the ability related to the convergence range can be measured without using the sense of depth as a clue, and the influence of accommodative convergence can be reduced. Here, "accommodative convergence" refers to the convergence (convergence divergence movement) that occurs simultaneously with the adjustment generated according to the viewing distance.

[0076] That is, according to this embodiment, the convergence range in a state where the stereoscopic perception of the subject is suppressed can be measured very easily. In this way, if the convergence range of the subject can be measured with high accuracy and very easily, by using the measurement result as one of the design parameters of the eyeglass lens, it is possible to provide an eyeglass lens suitable for the subject.

[0077] For example, for a subject who is considered to have weak motor fusion according to the measurement results, it is possible to provide a spectacle lens with the following lens design: since it is difficult to fuse in a state of strong binocular separation and it is easy to complain of diplopia, a prism is placed in the range where motor fusion can be performed as a supplement. In addition, for example, for a subject who is considered to have strong motor fusion according to the measurement results, it is possible to provide a spectacle lens with the following lens design: since there is a possibility that the Panum fusion area is wide, inset can be reduced without affecting fusion, and the maximum aberration amount on the nasal side can be reduced. In addition, "motor fusion" refers to fusion accompanied by eye movement to maintain single vision.

[0078] <System configuration example>

[0079] Next, the specific contents of this embodiment will be described.

[0080] (Structure of eyeglass lens manufacturing system)

[0081] Figure 1 1 is a block diagram showing the structure of a spectacle lens manufacturing system 1 for implementing the spectacle lens manufacturing method of the present embodiment. The spectacle lens manufacturing system 1 is, for example, installed in a spectacle lens manufacturing factory, such as Figure 1 As shown, there is a binocular vision function measurement system 10, an input device 20 (keyboard, mouse, game controller, etc.), a PC (Personal Computer) 30, a display 40, and a processing machine 50. In the PC 30, the measurement data of the binocular vision function of the subject measured using the binocular vision function measurement system 10 and the specification data of the eyeglass lens input by the input device 20 are input. The specification data includes, for example, the optical characteristics or product categories of the eyeglass lens. Among the optical characteristics of the eyeglass lens, for example, the vertex refractive power (spherical refractive power, astigmatism refractive power, astigmatism axis direction, prism refractive power, prism base direction) and the like are envisioned. The binocular vision function measurement system 10 and the input device 20 can also be set up in an eyewear store far away from the eyeglass lens manufacturing factory. In this case, the measurement data based on the binocular vision function measurement system 10 or the specification data input by the input device 20 are transmitted to the PC 30 via a computer network.

[0082] The PC 30 has a CPU (Central Processing Unit) 32, a HDD (Hard Disk Drive) 34, and a RAM (Random Access Memory) 36. A processing control program for controlling the processing machine 50 is installed in the HDD 34. The CPU 32 loads the processing control program into the RAM 36 and starts it. When the processing control program is started, a GUI (Graphical User Interface) for instructing the design and manufacture of eyeglass lenses is displayed on the display screen of the display 40. The processing control program selects a semi-finished lens based on the specification data and the measurement data, performs an optimization calculation of the surface shape, and determines the optical design value.

[0083] The operator places the selected semi-finished lens on the processing machine 50, operates the GUI, and inputs an instruction to start processing. The processing control program reads the determined optical design value and drives and controls the processing machine 50. The processing machine 50 grinds the surface of the finished lens according to the execution of the processing control program to manufacture the eyeglass lens. In addition, a specific design method of the eyeglass lens using the measurement data related to the binocular vision function is exemplified in, for example, the pamphlet of International Publication No. 2010 / 090144 proposed by the present applicant.

[0084] (Structure of binocular vision function measurement system)

[0085] Figure 2 1 is a diagram schematically showing a binocular vision function measurement system 10 . Figure 3 1 is a block diagram showing the structure of the binocular vision function measurement system 10. In the binocular vision function measurement method using the binocular vision function measurement system 10, multiple types of binocular vision functions of the subject 2 can be measured in order to obtain design data (or evaluation data) of eyeglass lenses that cannot be obtained by prescriptions focusing only on one eye.

[0086] like Figure 2 As well as Figure 3As shown, the binocular vision function measurement system 10 has a smart phone 110 as a portable information terminal. A portable information terminal is a small information electronic device that can be carried by a user, and is configured to have at least a display screen for displaying information. The smart phone 110 is a type of portable information terminal, and in addition to the function of a portable telephone, it is also configured to have the function of a small computer device. In addition, here, the portable information terminal is taken as an example of a smart phone 110, but it is not limited to this. For example, other portable information terminals such as a tablet terminal or a PDA (Personal Digital Assistant) can also be used.

[0087] The smartphone 110 has a display screen (mobile display screen) 111 composed of a single LCD (liquid crystal display) panel or an organic EL (electroluminescence) panel, etc. on one side. The area on the screen of the display screen 111 is divided into a right-eye image area 111R and a left-eye image area 111L. And, as will be described in detail later, it is configured to separately display a right-eye image to be visually recognized by the right eye 2R of the subject 2 in the right-eye image area 111R and a left-eye image to be visually recognized by the left eye 2L of the subject 2 in the left-eye image area 111L.

[0088] Furthermore, the smartphone 110 is supported by the support frame portion 112a so that the display screen 111 is located in front of the eyes of the subject 2. That is, when the support frame portion 112a is worn on the head of the subject 2, the display screen 111 of the smartphone 110 supported by the support frame portion 112a is located in front of the eyes of the subject 2. The smartphone 110 supported in this way has the display screen 111 arranged in the closed space formed by the support frame portion 112a, so that the image display for the subject 2 is performed in the space that cuts off the information (real space information) of the depth and perspective sense from the outside world.

[0089] In the sealed space formed by the supporting frame portion 112a, the partition wall 112b is preferably provided so as to be located between the right-eye image region 111R and the left-eye image region 111L of the display screen 111. This can prevent light from the right-eye image region 111R of the display screen 111 from reaching the left eye 2L of the subject 2, and prevent light from the left-eye image region 111L from reaching the right eye 2R of the subject 2.

[0090] That is, the smartphone 110 is supported by the support frame portion 112a worn on the head of the subject 2, and functions as an "optical target presenting unit" that presents the right eye image and the left eye image to the subject 2 while using a single display screen 111 in a space where the actual spatial information is cut off. In other words, the optical target presenting unit is configured to use the smartphone 110 located in front of the eyes of the subject 2.

[0091] When such a smartphone 110 is placed in front of the eyes of the subject 2, only the right eye image can be seen in the right eye 2R of the subject 2, and only the left eye image can be seen in the left eye 2L of the subject 2. Thus, within the Panum's fusion area, the subject 2 can fuse the parallax images of the right eye image area 111R and the left eye image area 111L even if the images are formed at non-corresponding points on the retina.

[0092] The supporting frame portion 112a supporting the smartphone 110 may be formed by molding a resin material, but the invention is not limited thereto and may be formed by other materials (eg, paper or metal). The same applies to the partition wall 112b.

[0093] In addition, the support frame portion 112a supporting the smartphone 110 may also have the following function: setting the viewing distance of the subject 2 for the right eye image and the left eye image to be variable. Specifically, in order to set the viewing distance to be variable, the support frame portion 112a may also be configured, for example, as follows: preparing a plurality of spacers (frame materials), and making the viewing distance variable by selectively wearing one of them. In addition, a lens with a certain refractive power may be provided between either or both of the left eye 2L and the left eye image area 111L, and between the right eye 2R and the right eye image area 111R. The lens may be a single lens, or a plurality of lenses may be combined to achieve the desired refractive power.

[0094] In addition, the smartphone 110 has a CPU 113, a memory 114, and an input device 115 in addition to a display screen 111, and is configured to function as a small computer device. As the input device 115, for example, a touch panel or the like superimposed on the display screen 111 can be exemplified. In addition, if a communication-type keyboard using short-range wireless communication is also provided, it is preferable in terms of improving the operability of the operator or the person being measured 2, etc.

[0095] A binocular vision function measurement program as a dedicated application for binocular vision function measurement is downloaded (installed) in the memory 114. The CPU 113 reads the binocular vision function measurement program from the memory 114 and starts it. When the binocular vision function measurement program is started, the CPU 113 functions as a presentation control unit 113a, a timing detection unit 113b, and a parameter value calculation unit 113c.

[0096] The presentation control unit 113a controls the image display operation in the right-eye image area 111R and the left-eye image area 111L of the display screen 111. Specifically, the presentation control unit 113a gives instructions to present the right-eye image in the right-eye image area 111R and the left-eye image in the left-eye image area 111L, and relatively changes the presentation positions of the right-eye image and the left-eye image. The specific method of relatively changing the presentation position will be described in detail later.

[0097] The right-eye image and the left-eye image presented by the presentation control unit 113 a function as parallax images and are therefore assumed to be composed based on graphics having the same shape and size. Specific examples of graphics constituting each image will be described in detail later.

[0098] When the presentation positions of the right eye image and the left eye image are relatively changed, the timing detection unit 113b detects the timing at which the subject 2 cannot fuse the right eye image with the left eye image. This timing detection may be performed based on the operation content of the subject 2 on the input device 115.

[0099] When the timing detection unit 113b detects the timing at which fusion is impossible, the parameter value calculation unit 113c calculates a predetermined parameter value for the binocular vision function of the subject 2 based on the relative positional relationship between the right eye image and the left eye image at that time. A specific example of the predetermined parameter value will be described in detail later.

[0100] In addition to these functions, the CPU 113 may function as a tracking ability determination unit 113 d by activating the binocular vision function measurement program.

[0101] The tracking ability determination unit 113d determines the degree of tracking ability of the eye of the subject 2 for the position change of the presented image. Specifically, when measuring the binocular vision function of the subject 2, multiple measurements are performed at different speeds of change of the relative positions of the right eye image and the left eye image, and it is determined to which degree the tracking ability of the eye of the subject 2 corresponds to the multiple stages set in advance.

[0102] Even if the relative position of the right-eye image and the left-eye image changes at a high speed, if the calculated predetermined parameter value is almost unchanged from the parameter value at a low speed, the tracking ability of the eye of the subject 2 is considered to be high. Generally, it is considered easier to cope with parallax that changes at a low speed than with a fast change, and therefore, the tracking ability of the eye of the subject 2 can be determined using the speed dependency of the parameter value obtained during a certain slow change as a reference.

[0103] The PC 130 is connected to the smartphone 110 configured as described above via a wired or wireless communication line. The display 140 is connected to the PC 130 .

[0104] In addition, in the system structure described above, if the smartphone 110 and the PC 130 can always communicate, the functions implemented in the smartphone 110 as the presentation control unit 113a, the timing detection unit 113b, the parameter value calculation unit 113c and the tracking capability determination unit 113d, and the function as the input device 115 can also be implemented in the PC 130.

[0105] In addition, in the system configuration described above, when all the components of the eyeglass lens manufacturing system 1 are installed at the same location, Figure 1 The PC30 shown is Figure 2 or Figure 3 The PC 130 shown may also be a single PC. Figure 1 The input device 20 shown is Figure 2 or Figure 3 The input device 115 shown may also be a single input device. Figure 1 The display 40 shown is Figure 2 or Figure 3 The display 140 shown may also be a single display.

[0106] <Binocular Vision Function Measurement Process>

[0107] Next, a description will be given of the specific contents of a binocular vision function measurement method according to the present embodiment, which is a process of measuring the binocular vision function using the binocular vision function measurement system 10 configured as described above.

[0108] When the binocular vision function is measured, the binocular vision function measurement program is started in the smartphone 110, and a GUI of various instructions for measuring the binocular vision function is displayed on the display screen 111. When the operator performs the GUI operation, the binocular vision function measurement program generates measurement data according to the GUI operation. When the smartphone 110 is supported by the support frame portion 112a and is located in front of the eyes of the person being measured 2, the smartphone 110 processes the measurement data, generates a right eye image and a left eye image for measuring the binocular vision function, and displays them in the right eye image area 111R or the left eye image area 111L of the display screen 111. Thus, the binocular vision function measurement is started.

[0109] The binocular vision function measurement program supports various measurement items related to binocular vision function, and outputs parameter values ​​for various measurement items as measurement results. Supported parameter values ​​include, for example, convergence range, left and right eye vertical divergence allowable value, first unequal magnification allowable value, second unequal magnification allowable value, left and right eye rotational parallax allowable value, etc. When the operator performs binocular vision function measurement, he selects any measurement item on the GUI.

[0110] In addition, the operator inputs age or viewing distance as measurement conditions. The input measurement conditions are stored in the memory 114. In addition, regarding the viewing distance, if the smartphone 110 or the support frame portion 112a has a function of setting the viewing distance as a variable, the viewing distance can be changed as needed.

[0111] Hereinafter, the execution of the processing of the binocular vision function measurement program when each of the measurement items listed above is selected will be described.

[0112] (When “Convergence Range” is selected)

[0113] The binocular vision function measurement program is transferred to the convergence range measurement mode for measuring the convergence range of the subject 2. The convergence range here is the convergence without accommodation. Here, the convergence (or divergence) and accommodation of the eyeball, as shown in the well-known Donders diagram, originally work in synergy. Therefore, it is not easy to separate the convergence from the accommodation and measure it. In addition, the Donders diagram is described in the following: "Ishihara Shinobu, Kano Shinichi revised "Micro-ophthalmology" 17th edition, Kanehara Publishing, (1925) p50", "Hata Toyohiko "Depth Information and Visual Characteristics" Visual Information Research Society, April 23, 1949, p12" ("Ishihara Shinobu, Kano Shinichi revised "Micro-ophthalmology" 17th edition, Kanehara Publishing, (1925) p50", "Hata Toyohiko "Okuki Information and Visual Characteristics" Visual Information Research Society, April 23, 1949, p12"), and the pamphlet of International Publication No. 2010 / 090144 proposed by the applicant of the present application. In the Donders diagram, a straight line with a slope of 1 (angle 45 degrees) passing through the origin is a Donders line. The Donders line represents the coordination of convergence and accommodation when the naked eye subject without strabismus or strabismus observes the object. On the left and right of the Donders line, the Donders curve indicating the limit value of convergence (or divergence) is drawn. From a point on the Donders line to the values ​​of the Donders curves on the left and right, the right side (the side where the convergence angle becomes larger) is classified as virtual relative convergence, and the left side (the side where the convergence angle becomes smaller) is classified as real relative convergence.

[0114] Figure 4 This is a diagram showing a flowchart of processing executed in the convergence range measurement mode based on the binocular vision function measurement program. Figure 5 This is a transition diagram of an image displayed on the display screen during execution of the convergence range measurement mode. In the following descriptions and drawings in this specification, the processing steps are abbreviated as "S".

[0115] When switching to the convergence range measurement mode, such as Figure 5 As shown in (a), the left-eye image 200L and the right-eye image 200R are displayed in the left-eye image area 111L and the right-eye image area 111R of the display screen 111 ( Figure 4 S1). The left-eye image 200L and the right-eye image 200R are the same image including size, color, shape, etc. Preferably, the left-eye image 200L and the right-eye image 200R are simple geometric shapes so that the person being measured 2 can focus on the measurement. In the example, the left-eye image 200L and the right-eye image 200R are shown as triangular shapes, but are not limited to this. For example, they may be straight lines (line segments) extending in the same direction and the same length, or other geometric shapes.

[0116] In addition, an instruction is given to the measured person 2 to perform a predetermined operation such as pressing an operation key of the input device 115 at the time when the image is seen to be double. The instruction is displayed, for example, in at least one of the right eye image area 111R or the left eye image area 111L. In addition, the operator may directly give the instruction to the measured person 2. The same instruction may be given when measuring other measurement items other than the convergence range.

[0117] exist Figure 4 In the processing of S2, Figure 5 As shown in (a), the left eye image 200L and the right eye image 200R are displayed in the right eye image area 111R and the left eye image area 111L, respectively, to check whether the subject 2 sees each image as double. Figure 4 In the process of S3 , the operator moves the right-eye image area 111R and the left-eye image area 111L farther away from or closer to each other until they reach a position where the double is no longer visible, and repeats this process until the double is no longer visible.

[0118] Specifically, for example, if it is a remote situation, such as Figure 5 As shown in (c), the left-eye image 200L and the right-eye image 200R are located in the horizontal direction ( Figure 5 The image 200L for the left eye and the image 200R for the right eye move away from each other in the direction of the arrow (c). The movement of the image moving away is depicted as a continuous change or a step-by-step change. The image 200L for the left eye and the image 200R for the right eye continue to move away from each other until a predetermined operation key of the input device 115 is pressed ( Figure 4 When the subject 2 presses the specified operation key, the positional offset between the left-eye image 200L and the right-eye image 200R at that moment (hereinafter, for convenience of explanation, referred to as the "first relative convergence measurement position") is stored in the memory 114 ( Figure 4 In addition, the positions of the left eye image 200L and the right eye image 200R may be relatively separated. Therefore, one of the left eye image 200L or the right eye image 200R may be fixed in position during measurement. The same is true in the left and right eye vertical dispersion allowable value measurement mode described later.

[0119] The presentation time of the moving-away image is appropriately set according to the tracking ability of the subject.

[0120] exist Figure 4 In the process of S5, the left-eye image 200L and the right-eye image 200R are measured from the first relative convergence position in the horizontal direction ( Figure 5The left-eye image 200L and the right-eye image 200R continue to approach each other until a predetermined operation key of the input device 115 is pressed ( Figure 4 When the subject 2 presses the specified operation key, the positional offset between the left-eye image 200L and the right-eye image 200R at that moment (hereinafter, for the sake of convenience, referred to as the "second relative convergence measurement position") is stored in the memory 114 ( Figure 4 S7).

[0121] Then, in Figure 4 In the process of S8, the left-eye image 200L and the right-eye image 200R are returned from the second relative convergence measurement position to the first relative convergence measurement position. After returning to the first relative convergence measurement position, Figure 4 In the process of S9, the left-eye image 200L and the right-eye image 200R are moved from the first relative convergence measurement position along the horizontal direction ( Figure 5 The left-eye image 200L and the right-eye image 200R continue to move away from each other until a predetermined operation key of the input device 115 is pressed ( Figure 4 When the subject 2 presses the specified operation key, the positional offset between the left-eye image 200L and the right-eye image 200R at that moment (hereinafter, for the sake of convenience, referred to as the "third relative convergence measurement position") is stored in the memory 114 ( Figure 4 of S11). Figure 4 The order of the processing of S5 or S9 and S8 can also be changed as follows. Figure 6 As shown, before the left and right parallax images are brought closer or farther away (S5, S9), by returning the parallax images to the first relative convergence measurement position each time (S8), the relative convergence can be measured without including the historical effect of convergence (S12). At this time, preferably, the approach amount and the distance amount are increased relative to the amount immediately before when two are not seen in the immediately before judgment, so the step of determining the approach amount or distance amount of the parallax images (S13, S14) can also be set before moving the respective parallax images.

[0122] exist Figure 4In the process of S12, the first vergence angle (divergence limit) and the second vergence angle (vergence limit) are calculated using the first relative vergence measurement position, the second relative vergence measurement position, the third relative vergence measurement position, and the viewing distance. The first vergence angle represents the actual relative vergence corresponding to the accommodative power at the viewing distance during measurement. The second vergence angle represents the virtual relative vergence corresponding to the accommodative power at the viewing distance during measurement. The viewing distance remains unchanged during measurement. Thus, the accommodative power of the subject 2 does not substantially change during measurement. Therefore, the actual relative vergence and the virtual relative vergence can be separated from accommodation and measured simply and with high precision.

[0123] If the actual relative vergence and the virtual relative vergence obtained in the process of S12 are applied to Donders' diagram, the left and right Donders' curves are estimated. That is, the coordination relationship between the vergence and accommodation of the subject 2 is obtained. Donders' curves vary depending on age. Therefore, when estimating Donders' curves, it is preferable to consider the age input as a measurement condition. Figure 4 If the measurement based on the vergence range measurement mode is performed by changing the viewing distance, the actual relative vergence and the virtual relative vergence when different accommodative actions are performed are measured. The more the measurement of the vergence range at different viewing distances is repeated, the more sample data for estimating Donders' curves are collected. Therefore, the coordination relationship between the vergence and accommodation of the subject 2 is obtained with higher precision.

[0124] An operator can appropriately set the speed of changing the relative change (movement, rotation, zoom, etc.) between the left-eye image 200L and the right-eye image 200R. Among them, the speed of the relative change that can be set is preferably a speed that converges within a specified range. The upper limit of the speed of the relative change is set, for example, to a value such that the error caused by the time lag between the timing when the subject cannot achieve fusion and the timing of pressing a specified operation key of the input device 115 converges to a specified allowable value. On the other hand, the lower limit is set, for example, to a value such that the display of the image changes before the fusion acts strongly and the fusion range expands beyond the range assumed in natural eye movements. The specific set values of the upper and lower limits are determined, for example, after repeated experiments and the like.

[0125]

[0126] ​In addition, if the binocular vision function measurement program realizes the function as the tracking ability determination unit 113d, by changing the speed of relative position change of the left eye image 200L and the right eye image 200R to obtain a plurality of convergence range values ​​as predetermined parameter values, it is possible to determine the degree of tracking ability of the eye of the subject 2 for the position change of the presented image. In this way, it is possible to reflect the degree of tracking ability of the eye of the subject 2 on the moving speed of the left eye image 200L and the right eye image 200R, so that the subject 2 can perform eye movement without any compulsion, and as a result, the binocular vision function of the subject 2 can be measured with high accuracy.

[0127] In order to measure the convergence range quickly and with high accuracy, the left eye image 200L and the right eye image 200R may be moved away from or close to each other multiple times. For example, in the first measurement (hereinafter, referred to as "preliminary measurement" for the sake of convenience), the left eye image 200L and the right eye image 200R are moved away from or close to each other at a high speed to specify the approximate position of the fusion limit. In the second measurement (hereinafter, referred to as "this measurement" for the sake of convenience), the left eye image 200L and the right eye image 200R are moved away from or close to each other at a relatively slow speed (however, a speed at which fusion does not strongly act) around the approximate position specified in the preliminarily measurement. In this measurement, since the moving speed of the presented image is slow, the error caused by the time lag between the timing when the subject 2 cannot fuse and the timing when the predetermined operation key of the input device 115 is pressed is suppressed, and the measurement accuracy is improved. In addition, the measurement interval of this measurement is limited to the approximate position around the fusion limit specified in the preliminarily measurement. Therefore, the measurement of the convergence range can be performed quickly even when both the pre-measurement and the current measurement are performed. Other measurement items outside the convergence range are also measured quickly and accurately, so both the pre-measurement and the current measurement can be performed.

[0128] The parameter value of the convergence range of the measured person 2 is obtained based on the real relative convergence and the virtual relative convergence measured in the convergence range measurement mode. Based on the parameter value, for example, it is possible to estimate the potential deviation (esotropia or exotropia) of the measured person 2. The parameter value can also be estimated for measurement items other than the convergence range in the same manner.

[0129] (When "Allowable vertical spread of left and right eyes" is selected)

[0130] The binocular vision function measurement program shifts to the left-right eye vertical divergence allowable value measurement mode for measuring the left-right eye vertical divergence allowable value of the subject 2. The left-right eye vertical divergence allowable value is the allowable value of the left-right eye vertical divergence that enables stereoscopic vision. Figure 7This is a diagram showing a flowchart of processing executed in the left-right eye vertical divergence allowable value measurement mode based on the binocular vision function measurement program. Figure 8 This is a transition diagram of an image displayed on the display screen during execution of the left-right eye vertical divergence allowable value measurement mode. In the following descriptions and drawings of this specification, the same or similar processes are denoted by the same or similar reference numerals and the description thereof is simplified or omitted.

[0131] When the left-eye vertical divergence allowable value measurement mode is switched to perform image display, the left-eye image 200L and the right-eye image 200R are displayed in the right-eye image area 111R and the left-eye image area 111L of the display screen 111 so that the left-eye image 200L and the right-eye image 200R appear to be separated ( Figure 7 S1 Figure 8 (a)). Then, if Figure 8 As shown in (b), the left-eye image 200L and the right-eye image 200R are arranged in the vertical direction ( Figure 8 (b)) and move away from ( Figure 7 When the subject 2 presses a specified operation key ( Figure 7 S3: "Yes"), the positional offset between the left-eye image 200L and the right-eye image 200R at that moment (hereinafter, for the sake of convenience, referred to as "the first left-right eye vertical divergence allowable value measurement position") is stored in the memory 114 ( Figure 7 S14).

[0132] exist Figure 7 In the process of S15, the left eye image 200L and the right eye image 200R are formed from the first left-right eye vertical dispersion allowable value measurement position along the vertical direction of the display screen ( Figure 8 The direction opposite to the arrow direction (b) is Figure 8 (c) arrow direction) moves and approaches, and then, as Figure 8 (c) As shown in FIG. 2, when the subject 2 presses a predetermined operation key ( Figure 7 S6: "Yes"), the positional offset between the left-eye image 200L and the right-eye image 200R at that moment (hereinafter, for the sake of convenience, referred to as "second left-right eye vertical divergence allowable value measurement position") is stored in the memory 114 ( Figure 7 of S17).

[0133] exist Figure 7In the process of S18, the left-right eye vertical divergence allowable value and the vertical range in which the object can be fused in the viewing distance are calculated based on the first and second left-right eye vertical divergence allowable value measurement positions and the viewing distance. When the viewing distance is changed and the left-right eye vertical divergence allowable value measurement mode is used, the left-right eye vertical divergence allowable value is measured when different accommodation forces are activated (for example, when looking at a near object or a far object).

[0134] (When "First Unequal Magnification Permit Value" is selected)

[0135] The first unequal magnification allowable value is the allowable value of the unequal magnification of the left and right eyes that can achieve stereoscopic vision. Whether to prescribe eyeglass lenses for unequal magnification is generally determined rigidly (spoon rule) based on whether the left and right visual acuity difference is 2 diopters or more. However, there are individual differences among patients, so even if the left and right visual acuity difference is less than 2 diopters, there are cases where fusion is difficult. In addition, on the contrary, there are cases where fusion is not difficult even if the left and right visual acuity difference is more than 2 diopters. In the first unequal magnification allowable value measurement mode described below, whether fusion is possible taking into account the left and right visual acuity difference is actually measured. Therefore, when using the results of the measurement based on the first unequal magnification allowable value measurement mode, the best prescription for unequal magnification that takes into account individual differences can be made.

[0136] The binocular vision function measurement program shifts to the first unequal magnification allowable value measurement mode for measuring the first unequal magnification allowable value of the subject 2 . Fig. 9 This is a diagram showing a flowchart of processing executed in the first unequal magnification allowable value measurement mode based on the binocular vision function measurement program. Fig.10 This is a transition diagram of an image displayed on the display screen during execution of the first unequal magnification allowable value measurement mode.

[0137] When the mode is switched to the first unequal magnification allowable value measurement mode, Fig.10 As shown in (a), the left eye image 200L and the right eye image 200R are displayed at positions slightly offset from each other in the fusion range of the subject 2 ( Fig. 9 The presentation positions of the left eye image 200L and the right eye image 200R are determined with reference to the measurement results of the convergence range or the left and right eye vertical divergence allowable value. In the case where the convergence range or the left and right eye vertical divergence allowable value is not measured, the operator makes a fine adjustment so that the positions of the left eye image 200L and the right eye image 200R converge to the fusion range of the measured person 2.

[0138] exist Fig. 9 In the processing of S22, Fig.10As shown in (b), the left-eye image 200L is displayed enlarged relative to the right-eye image 200R. The enlargement rate of the left-eye image 200L is a constant aspect ratio, and is depicted in a continuous change or a step-by-step change. The enlargement of the display of the left-eye image 200L continues until a predetermined operation key of the input device 115 is pressed ( Fig. 9 When the subject 2 presses the specified operation key ( Fig. 9 When S3: "Yes", the display magnification ratio of the left-eye image 200L and the right-eye image 200R at that moment (hereinafter, referred to as "first display magnification ratio" for convenience of explanation) is stored in the memory 114 ( Fig. 9 S24). In addition, in the first unequal magnification allowable value measurement mode, the display magnification ratio of the left eye image 200L and the right eye image 200R can be relatively changed. Therefore, the change given to the image can also be reduced instead of enlarged. In addition, during the measurement, the left eye image 200L and the right eye image 200R can be simultaneously enlarged or reduced at different magnifications. The same is true in the second unequal magnification allowable value measurement mode described later.

[0139] exist Fig. 9 In the processing of S25, Fig.10 As shown in (c), the right eye image 200R is displayed enlarged relative to the left eye image 200L. Fig. 9 When S6: "Yes", the display magnification ratio of the left-eye image 200L and the right-eye image 200R at that moment (hereinafter, referred to as "second display magnification ratio" for convenience of description) is stored in the memory 114 ( Fig. 9 of S27).

[0140] exist Fig. 9 In the processing of S28, the first unequal magnification allowable value in the viewing distance is calculated based on the first and second display magnification ratios and the viewing distance. When the viewing distance is changed and the measurement based on the first unequal magnification allowable value measurement mode is performed, the first unequal magnification allowable value is measured when different accommodation forces are activated (for example, when looking at a near object or a far object).

[0141] (When "Second Unequal Magnification Permit Value" is selected)

[0142] The binocular vision function measurement program shifts to the second unequal magnification allowable value measurement mode for measuring the second unequal magnification allowable value of the subject 2. The second unequal magnification allowable value is an allowable value of unequal magnification in a specific direction limited to the left and right eyes capable of stereoscopic vision. Fig.11 This is a diagram showing a flowchart of processing executed in the second unequal magnification allowable value measurement mode based on the binocular vision function measurement program. Fig.12This is a transition diagram of an image displayed on the display screen during execution of the second unequal magnification allowable value measurement mode.

[0143] After switching to the second unequal magnification allowable value measurement mode and displaying the image ( Fig.11 S21 Fig.12 (a)), the display of the left-eye image 200L in a specific direction is enlarged relative to the right-eye image 200R ( Fig.11 S32). Fig.12 In the image example (b), only the display magnification of the left-eye image 200L in the vertical direction of the screen is enlarged. The enlargement of the left-eye image 200L is depicted as a continuous change or a step-by-step change. The enlargement of the display of the left-eye image 200L continues until a predetermined operation key of the input device 115 is pressed ( Fig.11 When the subject 2 presses the specified operation key ( Fig.11 When S3: "Yes", the display magnification ratio of the left-eye image 200L and the right-eye image 200R in the vertical direction of the screen (hereinafter, for convenience of explanation, referred to as the "display magnification ratio in the first specific direction") at that moment is stored in the memory 114 ( Fig.11 S34).

[0144] exist Fig.11 In the process of S35, it is determined whether the left eye image 200L is enlarged for all specific directions of the zoom target. In this embodiment, the direction of the zoom target is the vertical direction of the screen and the horizontal direction of the screen. Therefore, the direction of the zoom target is changed to the horizontal direction of the screen ( Fig.11 S35: "No", S36). Then, Fig.12 As shown in (c), the left-eye image 200L is displayed in the horizontal direction of the screen with respect to the right-eye image 200R. Fig.11 When S3: "Yes"), the display magnification ratio of the left-eye image 200L and the right-eye image 200R in the horizontal direction of the screen (hereinafter, for convenience of explanation, referred to as "the display magnification ratio in the second specific direction") at that moment is stored in the memory 114 ( Fig.11 S34).

[0145] exist Fig.11 In the processing of S38, the second unequal magnification allowable value in the viewing distance is calculated based on the display magnification ratio of the first and second specific directions and the viewing distance. When the viewing distance is changed and the measurement based on the second unequal magnification allowable value measurement mode is performed, the second unequal magnification allowable value when different accommodation forces are activated (for example, when looking close or far away) is measured. The direction of the zoom object is not limited to the horizontal direction of the screen or the vertical direction of the screen, and may also include other directions.

[0146] (When "Allowable value for left-right eye rotational parallax" is selected)

[0147] Fusion rotation occurs when the directions of the lines of sight such as convergence are not parallel. The rotation of the eyeball when looking at a distant object is based on Listing's Law. Listing's Law is a law that determines the posture of the eyeball when it is facing a certain direction in space. The posture of the eyeball refers to the horizontal and vertical directions of the eyeball. If the posture of the eyeball is not determined, the up, down, left, and right directions of the retinal image are not determined. The posture of the eyeball cannot be determined solely by the line of sight, that is, the direction of the optical axis of the eyeball. When only the line of sight is determined, the posture of the eyeball can still take all directions of rotation around the line of sight as the axis.

[0148] Listing's law determines the posture of the eyeball in any direction of sight toward infinity. Regarding Listing's law, for example, in "Handbook of Visual Information Processing" p. 405, it is stated that "any rotation of a single eye can be considered to occur around an axis in a plane (Listing's plane)".

[0149] For the above statement of Listing's law, use Fig.13 The coordinate system shown is used for explanation. Fig.13 The coordinate system shown is a coordinate system with point R, which is the rotation center of the eyeball, as the origin, and the direction entering the eye from the front (horizontally forward) is defined as the X-axis direction, the vertical direction orthogonal to the X-axis direction is defined as the Y-axis direction, and the horizontal direction orthogonal to the X-axis direction is defined as the Z-axis direction. The Y-Z plane is the Listing's plane.

[0150] The posture of the eyeball in any direction after rotation is the same as the rotation about the straight line in the Listing's plane containing point R. Fig.13 In FIG. 1 , an example of a straight line that becomes the rotation axis is shown between the Y axis and the Z axis (on the Y-Z plane). The rotation axis is orthogonal to both the first eye position (X axis direction) and the line of sight direction after rotation. Here, consider the case where the eyeball rotates toward a direction vector (L, M, N) not shown in the figure. In this case, the respective vectors in the X axis direction, Y axis direction, and Z axis direction of the eyeball coordinate system after rotation are calculated using the following formula (1).

[0151] [Mathematical formula 1]

[0152] x=Li+Mj+Nk

[0153]

[0154]

[0155] For Listing's law, it is correct to determine the eyeball posture for an object at infinity with one eye. In addition, for example, when the body is tilted to view an object at infinity, the eyeball posture is the same in the left eye and the right eye, and the eyeball rotation is also the same. On the other hand, when viewing an object not at infinity with both eyes, the eyeball posture is different in the left eye and the right eye.

[0156] Fig.14 14A and 14B are diagrams showing the sight lines of the left and right eyes for explaining binocular vision. Fig.14 In each of Figures 14A and 14B, the dotted line indicates an imaginary eyeball 55 disposed at the middle position between the left eyeball 51L and the right eyeball 51R. Fig.14 As shown in A, the eyeball 51L and the eyeball 51R face the same viewing direction. The left and right eyeballs obey Listing's law, so the postures after rotation are also the same. At this time, there is no difference in the retinal images of the left and right eyes.

[0157] On the other hand, in the case of viewing an object at a finite distance (point A), if Fig.14 As shown in B, convergence is required. In this case, the viewing directions of eyeball 51L and eyeball 51R are different, so the rotation amount of the eyeball is different on the left and right. Fig.14 In B, point A is in the front left. Therefore, the rotation amount of the eyeball 51R is greater than the rotation amount of the eyeball 51L.

[0158] In the eye rotation based on Listing's law, the eye posture after rotation, that is, the direction vectors of the Y axis and Z axis after rotation, depends on the viewing direction vector shown in formula (1). When the viewing direction vectors of the left eye and the right eye are different, the direction vectors of the Y axis and Z axis after rotation are inconsistent in the left and right eyes. Therefore, the retinal image is rotationally offset. In order to eliminate the rotational offset of the retinal image, a rotation around the line of sight is required in the left and right eyes. This rotation around the line of sight is a fusional rotation.

[0159] When fusion rotation occurs, rotational parallax is generated in the left and right eyes. In the binocular vision function measurement program, the left and right eye rotational parallax allowable value, which is the allowable value of the rotational parallax of the left and right eyes that enables stereoscopic vision, can be measured. When the measurement item "left and right eye rotational parallax allowable value" is selected, the binocular vision function measurement program shifts to the left and right eye rotational parallax allowable value measurement mode for measuring the left and right eye rotational parallax allowable value of the subject 2. Fig.15 This is a diagram showing a flowchart of processing executed in the left-right eye rotational parallax allowable value measurement mode based on the binocular vision function measurement program. Fig.16 This is a transition diagram of an image displayed on the display screen during execution of the left-right eye rotational parallax allowable value measurement mode.

[0160] After switching to the left-right eye rotational parallax allowable value measurement mode and performing image display ( Fig.15 S21 Fig.16 (a)) Fig.16 As shown in (b), the left eye image 200L rotates counterclockwise ( Fig.15 The rotation of the left-eye image 200L is depicted as a continuous change or a step-by-step change. The rotation of the left-eye image 200L continues until a predetermined operation key of the input device 115 is pressed ( Fig.15 When the subject 2 presses a predetermined operation key ( Fig.15 S3: "Yes"), the rotation angle difference between the left-eye image 200L and the right-eye image 200R at that moment (hereinafter, referred to as "first rotation angle difference" for convenience of explanation) is stored in the memory 114 ( Fig.15 In S44 of FIG. 14 , the rotation center of the image is set to the center of gravity of the image. In the left-eye and right-eye rotation parallax allowable value measurement mode, the rotation angle difference between the left-eye image 200L and the right-eye image 200R may be relatively changed. Therefore, during the measurement, the left-eye image 200L and the right-eye image 200R may be rotated simultaneously at different speeds or in different directions.

[0161] exist Fig.15 The S45 process, such as Fig.16 As shown in (c), the left eye image 200L rotates clockwise. Fig.15 When S6: "Yes", the rotation angle difference between the left-eye image 200L and the right-eye image 200R at that moment (hereinafter, referred to as "second rotation angle difference" for convenience of explanation) is stored in the memory 114 ( Fig.15 S47).

[0162] exist Fig.15 In the processing of S48, the left-right eye rotational parallax allowable value in the viewing distance is calculated based on the first and second rotation angle differences and the viewing distance. When the viewing distance is changed to perform the measurement based on the left-right eye rotational parallax allowable value measurement mode, the left-right eye rotational parallax allowable value when different accommodation forces are activated (for example, when looking at a near object or a far object) is measured. By measuring the left-right eye rotational parallax allowable value at each different viewing distance, for example, in the case of prescribing progressive refractive glasses, it is possible to correct astigmatism to the best by prescribing different astigmatism axes in the far and near parts.

[0163] (For other measurements)

[0164] The binocular vision function measurement system 10 can also be used to measure the stereoscopic function. In the measurement of stereoscopic vision, for example, two types of parallax images of different shapes are displayed in the right eye image area 111R and the left eye image area 111L of the display screen 111. The parallax image is preferably a simple geometric shape such as ○ or △ so that the subject 2 can concentrate on the measurement. In this embodiment, the two types of parallax images are set as ○ image and △ image. The parallax of the ○ image is larger than that of the △ image. Therefore, the subject 2 sees the ○ image in front and the △ image in the back. Then, the parallax of at least one of the ○ image and the △ image is changed continuously or stepwise. The subject 2 presses a predetermined operation key of the input device 115 at a time when the depth of the ○ image and the △ image cannot be felt or when a double image is seen. The parallax of the image at the time when the predetermined operation key is pressed is stored in the memory 114. The CPU 113 calculates the limit of the subject 2 being able to see stereoscopically based on the parallax of the stored image and the viewing distance.

[0165] (Combined measurement of measurement items)

[0166] In each of the above-mentioned measurement modes, one measurement item is measured. In other measurement modes, a composite measurement of multiple measurement items (for example, at least two of the convergence range, the left and right eye upper and lower divergence allowable value, the first unequal magnification allowable value, the second unequal magnification allowable value, and the left and right eye rotational parallax allowable value) can also be performed simultaneously. In particular, when a plurality of closely connected and inseparable measurement items are simultaneously measured, there is a possibility of obtaining measurement results that cannot be grasped only by the measurement results of each measurement item alone. The operator can arbitrarily select the measurement items to be measured simultaneously. Some combinations of measurement items can also be prepared in advance. Three examples of composite measurement examples are described below.

[0167] (Composite determination of the convergence range - the allowable values ​​of the upper and lower divergence of the left and right eyes)

[0168] For example, the interaction between the convergence range and the vertical divergence is strong. Therefore, in the first composite measurement mode, at least one of the left eye image 200L or the right eye image 200R is moved continuously or stepwise along the screen tilt direction to perform simultaneous measurement of the convergence range and the left and right eye vertical divergence allowable value. Here, the screen tilt direction is any direction other than the horizontal direction of the screen or the vertical direction of the screen, and includes two components: the horizontal direction component of the screen and the vertical direction component of the screen. That is, in the left eye image 200L or the right eye image 200R, a display change is given that is a synthesis of the various change modes (movement in the horizontal direction of the screen and the vertical direction of the screen) in the convergence range measurement mode and the left and right eye vertical divergence allowable value measurement mode (hereinafter, for the sake of convenience, it is referred to as "composite change"). The angle of the screen tilt direction can be set by the operator or predetermined by the binocular vision function measurement program.

[0169] Fig.17 1 is an example of an image display in the first composite measurement mode. The flowchart of the first composite measurement mode is the same as the flowchart of the convergence range measurement mode, etc., and therefore is omitted. Fig.17 In the example of , the left eye image 200L moves from the dotted line position in the figure along the screen tilt direction. The movement in the screen tilt direction continues until the specified operation key of the input device 115 is pressed. When the subject 2 presses the specified operation key, the position offset between the left eye image 200L and the right eye image 200R at that moment is stored in the memory 114. In a series of measurements, the left eye image 200L or the right eye image 200R can be moved along different screen tilt directions to collect a plurality of position offset data. Based on each position offset and viewing distance stored in the memory 114, a composite measurement result of the convergence range in the viewing distance and the upper and lower divergence allowable values ​​of the left and right eyes is calculated. When the viewing distance is changed and the measurement based on the first composite measurement mode is performed, a composite measurement result is obtained when different accommodation forces are activated (for example, when looking at a near object or a far object).

[0170] (Compound determination of the convergence range - left and right eye up and down divergence allowance - second unequal magnification allowance (or first unequal magnification allowance))

[0171] For example, the interaction between the convergence range, the vertical divergence, and the unequal magnification of the left and right eyes is strong. Therefore, in the second composite measurement mode, at least one of the left eye image 200L or the right eye image 200R is moved continuously or stepwise along the tilt direction of the screen, and the display is enlarged or reduced. When the enlargement or reduction of the image is limited to a specific direction, it becomes the measurement of the second unequal magnification allowable value, and when the aspect ratio is fixed, it becomes the measurement of the first unequal magnification allowable value. In the left eye image 200L or the right eye image 200R, a composite change is given by synthesizing the various change modes (movement in the horizontal direction of the screen, vertical direction of the screen, change of display magnification) in the convergence range measurement mode, the left and right eye vertical divergence allowable value measurement mode, and the second unequal magnification allowable value (or the first unequal magnification allowable value) measurement mode. The proportion in which each change mode is given can be set by the operator or predetermined by the binocular vision function measurement program.

[0172] Fig.18 2 is an example of an image display in the second composite measurement mode. The flowchart of the second composite measurement mode is the same as the flowchart of the convergence range measurement mode, etc., and therefore is omitted. Fig.18 In the example of , the left eye image 200L moves from the dotted line position in the figure along the tilt direction of the screen and is enlarged only in the vertical direction of the screen. The movement and enlargement of the left eye image 200L continue until the specified operation key of the input device 115 is pressed. When the measured person 2 presses the specified operation key, the position offset amount of the left eye image 200L and the right eye image 200R at that moment and the display magnification ratio in the vertical direction of the screen (hereinafter, for the convenience of explanation, referred to as "image change state") are stored in the memory 114. In a series of measurements, the movement and enlargement of the left eye image 200L or the right eye image 200R can be repeated in different modes to collect multiple image change state data. Based on each image change state and viewing distance stored in the memory 114, a composite measurement result of the convergence range in the viewing distance, the left and right eye upper and lower divergence allowance, and the second unequal magnification allowance (or the first unequal magnification allowance) is calculated. When the viewing distance is changed and the measurement is performed in the second composite measurement mode, composite measurement results are obtained when different accommodation forces are activated (for example, when looking at something close or looking at something far away).

[0173] (Composite determination of the convergence range and the allowable value of the left and right eye rotational parallax)

[0174] As described above, fusional rotation occurs with convergence. Therefore, in the third composite measurement mode, at least one of the left eye image 200L or the right eye image 200R is moved continuously or in stages in the horizontal direction of the screen, and is rotated clockwise or counterclockwise. That is, in the left eye image 200L or the right eye image 200R, a composite change is given that synthesizes the various change modes (movement in the horizontal direction of the screen, rotation centered on the center of gravity of the image) in the convergence range measurement mode and the left and right eye rotational parallax allowable value measurement mode. The proportion in which each change mode is given can be set by the operator or predetermined by the binocular vision function measurement program.

[0175] Fig.19 2 is an example of an image display in the third composite measurement mode. The flowchart of the third composite measurement mode is the same as the flowchart of the convergence range measurement mode, etc., and therefore is omitted. Fig.19 For example, the left eye image 200L and the right eye image 200R move and move away in the horizontal direction of the screen respectively, while rotating counterclockwise and clockwise. The movement and rotation of the left eye image 200L and the right eye image 200R continue until the specified operation key of the input device 115 is pressed. When the measured person 2 presses the specified operation key, the position offset and the rotation angle difference of the left eye image 200L and the right eye image 200R at that moment are stored in the memory 114. In a series of measurements, the movement and rotation of the left eye image 200L or the right eye image 200R can be repeated in different modes to collect a plurality of position offset and rotation angle difference data. Based on each position offset and rotation angle difference and the viewing distance stored in the memory 114, a composite measurement result of the convergence range in the viewing distance and the left and right eye rotational parallax allowable value is calculated. When the viewing distance is changed and the measurement is performed in the third composite measurement mode, composite measurement results are obtained when different accommodation forces are activated (for example, when looking at something close or looking at something far away).

[0176] (For measurement taking side view into account)

[0177] In each of the above-mentioned measurement modes, the left-eye image 200L and the right-eye image 200R are displayed in the center of the display screen. Therefore, the measurement results can only be obtained when the subject 2 is in the frontal view state. Therefore, in each of the measurement modes, after the measurement in the frontal view state, the presentation positions of the left-eye image 200L and the right-eye image 200R are changed, for example Fig. 20As shown, the smartphone 110 is moved to the periphery of the display screen (upper left corner of the screen). Although the smartphone 110 is supported, since the support frame portion 112a is worn on the head of the person being measured 2 and the respective positional relationship is fixed, the left eye image 200L and the right eye image 200R are naturally viewed sideways. When the measurement is performed in this state, the measurement result is obtained when the person being measured 2 is viewing sideways. Furthermore, when the left eye image 200L and the right eye image 200R are sequentially moved to other positions around the screen (the center of the upper end of the screen, the upper right corner of the screen, the center of the right end of the screen, the lower right corner of the screen...) for measurement, the measurement results in the side-viewing state in various directions are obtained. Side-viewing, for example, must be accompanied by fusional rotation, which is different from the conditions for frontal viewing. Therefore, a measurement result different from that of the frontal viewing is obtained. When the design of the eyeglass lenses is also considered in consideration of the measurement results, a more suitable prescription becomes possible.

[0178] <Effects of the present embodiment>

[0179] According to the present embodiment, one or more of the following effects are obtained.

[0180] (a) In the present embodiment, when the binocular vision function of the subject 2 is measured, a right eye image and a left eye image (i.e., a parallax image) are presented to the subject 2 on a single movable display screen 111. Specifically, for example, the display screen 111 of the smartphone 110 is divided into a right eye image area 111R and a left eye image area 111L, and the parallax image is displayed to the subject 2 by displaying the right eye image in the right eye image area 111R and the left eye image in the left eye image area 111L. Therefore, a large system structure such as a fixed three-dimensional compatible video monitor is not required, and the parallax image can be presented by a very simple structure such as a single display screen 111, which is very preferable in seeking to simplify the measurement of the binocular vision function of the subject 2.

[0181] Furthermore, by using the movable display screen 111, it is very easy to position the display screen 111 in front of the eyes of the subject 2. In this regard, it is very preferable to simplify the measurement of the binocular vision function of the subject 2. Furthermore, by keeping the display screen 111 in front of the eyes of the subject 2, the error of the left and right parallax image positions with respect to the median plane can be kept constant regardless of the direction of the face of the subject 2. Therefore, it is preferable to wear the display screen 111 on the subject 2 so as to eliminate the error of the left and right parallax image positions.

[0182] Furthermore, when the movable display screen 111 is used, the parallax image can be easily presented in a space where the real space information is cut off by shielding its surroundings. If the parallax image is presented in a space where the real space information is cut off, the subject 2 does not obtain information (real space information) for feeling depth and perspective from the outside world except for the presented parallax image. Therefore, the subject 2 can measure the ability related to binocular vision function with high accuracy without using depth perception as a clue.

[0183] That is, according to the present embodiment, by presenting parallax images on the single movable display screen 111 , the binocular vision function of the subject 2 can be measured with high accuracy and very simply.

[0184] (b) In this embodiment, the display screen 111 of a smartphone 110, which is a type of portable information terminal, is used as a movable display screen to measure the binocular vision function of the person being measured. Therefore, it is possible to easily and reliably present a parallax image on a single movable display screen, and the introduction cost for this can also be suppressed. Therefore, it is preferable to measure the binocular vision function with high accuracy and very simply.

[0185] (c) As described in the present embodiment, by calculating the value of the convergence range of the subject 2 as the prescribed parameter value for the binocular vision function of the subject 2, the convergence range of the subject 2 can be measured with high accuracy and very simply. Furthermore, by using the measurement result as one of the design parameters of the eyeglass lens, it is possible to provide an eyeglass lens suitable for the subject 2.

[0186] (d) As described in the present embodiment, if the speed of the position change of the presented image is determined based on the determination result after determining the degree of tracking ability of the eyes of subject 2 with respect to the position change of the presented image, the degree of tracking ability of the eyes of subject 2 is reflected in the speed of the position change of the left presented image, so that subject 2 can perform eye movements without any effort, and as a result, the binocular vision function of subject 2 can be measured with high precision.

[0187] <Modifications, etc.>

[0188] Although the embodiments of the present invention have been described above, the above disclosures are only exemplary embodiments of the present invention. That is, the technical scope of the present invention is not limited to the above exemplary embodiments, and various modifications can be made without departing from the gist thereof.

[0189] For example, in the above-mentioned embodiment, the case where the display screen 111 of the smartphone 110 is used to display the parallax image on a single movable display screen is exemplified, but the present invention is not limited to this, and the parallax image can also be presented using the display screen of other portable information terminals such as tablet terminals or PDAs.

[0190] In addition, for example, in the above-mentioned embodiment, the moving speed, rotation speed, and zoom speed of the left-eye image 200L or the right-eye image 200R are described as being constant. However, the present invention is not limited thereto, and the left-eye image 200L or the right-eye image 200R may also be moved, rotated, or zoomed at an accelerated speed.

[0191] Explanation of symbols

[0192] 1…eyeglass lens manufacturing system, 10…binocular vision function measurement system, 20…input device, 30, 130…PC, 40, 140…display, 50…processing machine, 110…smartphone, 111…display screen, 111R…image area for right eye, 111L…image area for left eye, 113…CPU, 113a…presentation control unit, 113b…timing detection unit, 113c…parameter value calculation unit, 113d…tracking ability determination unit, 200R…image for right eye, 200L…image for left eye.

Claims

1. A method for measuring binocular vision function, comprising: a step of presenting an optotype, presenting, on a single movable display screen, to the subject an image for the right eye to be visually recognized by the subject's right eye and an image for the left eye to be visually recognized by the subject's left eye; A presentation control step of relatively changing presentation positions of the right-eye image and the left-eye image; a timing detection step of detecting a timing at which the subject cannot fuse the right-eye image with the left-eye image when the presentation position is changed; a parameter value calculating step of calculating a predetermined parameter value for the binocular vision function of the subject based on the relative positional relationship between the right-eye image and the left-eye image when the timing is detected; as well as The viewing distance setting step selects and sets any one of a plurality of viewing distances of the subject with respect to the right-eye image and the left-eye image.

2. The binocular vision function measurement method according to claim 1, wherein: The right-eye image and the left-eye image are presented using a display screen of a portable information terminal as the movable display screen.

3. The binocular vision function measurement method according to claim 1 or claim 2, wherein: The predetermined parameter value is a value that specifies the convergence range of the person being measured.

4. The binocular vision function measurement method according to claim 1 or claim 2, comprising: The tracking ability determination step determines the degree of tracking ability of the subject's eye for position changes of the presented image by changing the speed at which the relative positions of the right-eye image and the left-eye image change to obtain a plurality of the predetermined parameter values.

5. The binocular vision function measurement method according to claim 1 or claim 2, wherein: The right-eye image and the left-eye image are composed of graphics having the same shape and size. 6 . A binocular vision function measurement program for causing a computer to execute the binocular vision function measurement method according to claim 1 .

7. A method for designing eyeglass lenses, comprising: A step of measuring the binocular vision function of a subject using the binocular vision function measuring method according to any one of claims 1 to 5; and A step of determining optical design values ​​of eyeglass lenses based on the measurement results of the binocular vision function.

8. A method for manufacturing eyeglass lenses, comprising: A step of designing a spectacle lens using the spectacle lens design method according to claim 7; and The step of manufacturing the eyeglass lens according to the design result of the eyeglass lens.

9. A binocular vision function measurement system, comprising: an optotype presenting unit that presents, on a single movable display screen, to the subject an image for right eye visually recognized by the subject's right eye and an image for left eye visually recognized by the subject's left eye; a presentation control unit that relatively changes presentation positions of the right-eye image and the left-eye image; a timing detection unit that detects a timing at which the subject cannot fuse the right-eye image with the left-eye image when the presentation position is changed; a parameter value calculation unit that calculates a predetermined parameter value for the binocular vision function of the subject based on the relative positional relationship between the right-eye image and the left-eye image at the time when the timing is detected, and The support frame portion is used to select and set any one of a plurality of viewing distances of the subject with respect to the right-eye image and the left-eye image.

10. The binocular vision function measurement system according to claim 9, wherein: The optotype presenting unit is configured to present the right-eye image and the left-eye image using a display screen of the portable information terminal as the movable display screen.

Images