Vision detection method and system based on spatial arbitrary position

Abstract

This invention discloses a vision testing method and system based on arbitrary spatial location. The method includes: obtaining the geometric center of the optotype; constructing a three-dimensional coordinate system with the geometric center as the origin; obtaining the position information of the subject's eyes in the three-dimensional coordinate system; determining the subject's horizontal viewing angle relative to the smallest horizontal optotype and vertical viewing angle relative to the smallest vertical optotype based on the subject's distinguishable smallest horizontal optotype, smallest vertical optotype, and position information; and determining the subject's standard visual acuity value based on the horizontal and vertical viewing angles. The method and system of this invention can realize vision testing at any spatial location, by one or multiple people simultaneously. It has high testing efficiency and accuracy, exceeding the national standard of 0.1° visual angle (5-minute recording method), and has wide applicability and strong practicality.

Description

Technical Field

[0001] This invention discloses a vision detection method and system based on arbitrary spatial location, belonging to the field of vision detection technology. Background Technology

[0002] The national standard for normal vision defines normal vision as the ability to distinguish a 1' angle of view, recorded as 5 points, or 5.0, equivalent to 1.0 visual acuity in decimal notation, or 6 / 6 or 20 / 20 visual acuity in fractional notation. Optotypes used in vision standards include letter optotypes, number optotypes, and picture optotypes, each with fixed design standards. Taking the commonly used "E"-shaped letter optotype as an example, its design uses a square "E" shape with three equally long strokes, where each stroke or gap is one-fifth the side length of the square. Figure 1 As shown.

[0003] When using optotypes for visual acuity testing, national standards require a fixed distance between the test subject and the optotype, and the optotype itself must also be fixed, such as in national standard GB 11533-2011. For ease of operation, the standard only specifies the standards for distance visual acuity testing at 5m and near visual acuity testing at 25cm, meaning only the fixed design standard for the optotype "E" and its corresponding visual acuity test value are defined. Simultaneously, the standard requires that the test subject and the optotype be at the same horizontal level, looking directly at each other. The phrase "at the same horizontal level, looking directly at each other" emphasizes that the test subject must be at the same horizontal level as the optotype. Figure 2 As shown, when a person's eyes are looking straight ahead, the height of the ground is E1, and the center (white dot) of the optotype "E" (black) is E2.

[0004] The expression for equal horizontal height is:

[0005] E1 = E2 (Formula 1)

[0006] The expression for direct eye contact is:

[0007] Formula 2

[0008] Therefore, if the distance and / or angle between the test subject and the visual target differs from the standard during the vision test, an accurate vision test value cannot be obtained. For example, regarding angle of view:

[0009] ① There is a vertical angle between the subject and the visual target: The subject must be at the same height as the center of the visual target, otherwise it is impossible to guarantee that each stroke or gap in the vertical direction is a 1' angle.

[0010] Taking a horizontal sight (where the opening of E faces to the right) as an example, such as Figure 3 As shown, the height of the white subject on the left is E1′(x,y), and the height of the gray standard subject on the right is E1(x,y). They are the same height, as shown in Formula 3.

[0011] y E1 =y E1′ Formula 3

[0012] Therefore, the center of the new optotype E2′(x,y) corresponding to the white subject is Δe higher than the center of the standard optotype E2 on the right, meaning that the white subject and the center of the new optotype are not at the same horizontal level.

[0013] y E2′ -y E2 =△e

[0014] ∵y E1 =y E1′ y E2 =y E1 Formula 4

[0015] ∴y E2′ -y E1′ =△e

[0016] At this point, the gap angle of the new optotype is less than 1', that is, α′<1′, which does not meet the standard of the optotype. Consequently, when performing visual acuity testing, an accurate visual acuity test value cannot be obtained.

[0017] ② There is a horizontal angle between the subject and the visual target: The subject must be perpendicular to the horizontal plane of the visual target, otherwise it is impossible to guarantee that each stroke or gap in the horizontal direction is a 1' angle.

[0018] Taking a vertical target (where the opening of E faces upwards) as an example, such as Figure 4 As shown, the height of the white subject on the left is E1′(x,y), and the height of the gray standard subject on the right is E1(x,y). They are the same height, but there is a horizontal difference △e′ between them and the standard, as shown in Formula 5.

[0019] Formula 5

[0020] For the white subject on the left, his horizontal and vertical visual target at the same height is E2′(x,y), so the white subject and... Figure 4 The standard gray figure corresponds to the same height as the optotype E2(x,y), but there is horizontal parallax, which is:

[0021] Formula 6

[0022] If the standard optotype E2 is still used for white subjects, there will be horizontal parallax, that is: α′≠α and α′<1′, which does not meet the standard of the optotype. Consequently, the visual acuity test will not yield an accurate visual acuity value.

[0023] ③ When the subject and the optotype have both horizontal and vertical angles, whether it is a horizontal or vertical optotype, there will be standard gaps or strokes that do not conform to the design standard of 1′ angle. Consequently, when conducting a visual acuity test, an accurate visual acuity test value cannot be obtained. Summary of the Invention

[0024] The purpose of this application is to provide a vision detection method and system based on arbitrary spatial location, so as to solve the technical problem in the prior art that it is difficult to determine accurate vision detection values ​​at arbitrary spatial location.

[0025] The first aspect of the present invention provides a vision detection method based on arbitrary spatial location, comprising:

[0026] Step 1: Obtain the geometric center of the target and construct a three-dimensional coordinate system with the geometric center as the origin;

[0027] Step 2: Obtain the position information of the subject's eyes in the three-dimensional coordinate system;

[0028] Step 3: Based on the smallest distinguishable horizontal target, the smallest vertical target, and the position information of the subject, determine the subject's horizontal viewing angle relative to the smallest horizontal target and the vertical viewing angle relative to the smallest vertical target; the horizontal target is a target with its opening facing left or right, and the vertical target is a target with its opening facing up or down.

[0029] Step 4: Determine the standard visual acuity value of the subject based on the horizontal and vertical viewing angles.

[0030] Preferably, determining the subject's horizontal viewing angle relative to the minimum horizontal target and vertical viewing angle relative to the minimum vertical target specifically includes:

[0031] Obtain the first length between the midpoints of the left and right sides of the minimum horizontal target, and determine the horizontal viewing angle of the subject relative to the minimum horizontal target based on the first length and the position information;

[0032] Obtain the second length between the midpoints of the upper and lower sides of the minimum vertical target, and determine the vertical viewing angle of the subject relative to the minimum vertical target based on the second length and the position information.

[0033] Preferably, determining the horizontal viewing angle of the subject relative to the minimum horizontal target specifically includes:

[0034] The horizontal angle of the subject relative to the minimum horizontal target is determined according to the first formula, which is:

[0035]

[0036] In the formula: ∠LPR is the horizontal viewing angle, LR is the first length between the midpoints of the left and right sides of the minimum horizontal target, and P x P represents the x-axis coordinate of the subject in the three-dimensional coordinate system. y P represents the y-axis coordinate of the subject in the three-dimensional coordinate system. z Let z be the z-axis coordinate of the subject in the three-dimensional coordinate system.

[0037] Preferably, determining the vertical angle of the subject relative to the minimum vertical target specifically includes:

[0038] The vertical angle of the subject relative to the minimum vertical target is determined according to the second formula, which is:

[0039]

[0040] In the formula, ∠UPD is the vertical viewing angle, UD is the first length between the midpoints of the upper and lower sides of the minimum vertical target, and P x P represents the x-axis coordinate of the subject in the three-dimensional coordinate system. y P represents the y-axis coordinate of the subject in the three-dimensional coordinate system. z Let z be the z-axis coordinate of the subject in the three-dimensional coordinate system.

[0041] Preferably, determining the standard visual acuity value of the subject based on the horizontal and vertical viewing angles specifically includes:

[0042] The standard visual acuity value of the test subject is determined according to the third formula, which is:

[0043] LES = 5.699 - lgα

[0044] In the formula, LES is the standard visual acuity value, which is the logarithmic visual acuity value, α=min(∠LPR,∠UPD), ∠LPR is the horizontal visual angle, and ∠UPD is the vertical visual angle.

[0045] Preferably, determining the standard visual acuity value of the subject based on the horizontal and vertical viewing angles specifically includes:

[0046] Compare the horizontal viewpoint and the vertical viewpoint;

[0047] When the horizontal angle of view is smaller than the vertical angle of view, the standard visual acuity value of the subject is determined by using the horizontal angle of view corresponding to the minimum horizontal optotype.

[0048] When the vertical angle is less than or equal to the horizontal angle, the standard visual acuity value of the subject is determined using the vertical angle corresponding to the minimum vertical optotype.

[0049] Preferably, the subject of the test is one or more.

[0050] Preferably, the horizontal viewing angle is less than ±60° and the vertical viewing angle is less than ±30°.

[0051] A second aspect of the present invention provides a vision detection system based on arbitrary spatial location, comprising:

[0052] A coordinate construction module is used to obtain the geometric center of the standard target and construct a three-dimensional coordinate system with the geometric center as the origin.

[0053] A position determination module, which is used to obtain the position information of the subject's eyes in the three-dimensional coordinate system;

[0054] A viewing angle determination module is used to determine the horizontal viewing angle of the subject relative to the minimum horizontal visual target and the vertical viewing angle of the subject relative to the minimum vertical visual target based on the minimum horizontal visual target, the minimum vertical visual target, and the position information; the horizontal visual target is a visual target with an opening facing left or right, and the vertical visual target is a visual target with an opening facing up or down.

[0055] A vision determination module is used to determine the standard visual acuity value of the subject based on the horizontal and vertical viewing angles.

[0056] The vision detection method and system based on arbitrary spatial location of the present invention have the following advantages compared with the prior art:

[0057] The method and system of the present invention can realize vision detection at any location in space, by one person or multiple people at the same time, with high detection efficiency; furthermore, the method and system of the present invention have high detection accuracy, up to the minimum resolution of the human eye, 1' to 1.5', that is, 1 / 60° (0.017°), which is higher than the national standard of 0.1° angle of view (5-minute recording method), and can be applied in a wide range of scenarios with strong practicality. Attached Figure Description

[0058] Figure 1 This is a schematic diagram of the structure of an "E"-shaped visual target in the prior art;

[0059] Figure 2 This is a diagram illustrating the national standard vision testing process in existing technologies.

[0060] Figure 3 A comparison diagram of the visual acuity testing process for subjects under non-horizontal and horizontal direct gaze in existing technologies;

[0061] Figure 4A comparison diagram of the visual acuity testing process for subjects when they are not looking directly at each other and when they are looking directly at each other in the existing technology;

[0062] Figure 5 This is a flowchart of a vision detection method based on arbitrary spatial location in an embodiment of the present invention;

[0063] Figure 6 In this embodiment, (a) is the standard horizontal target and (b) is the standard vertical target.

[0064] Figure 7 This is a diagram showing the positions of the visual targets and the test subject in the classroom in an embodiment of the present invention;

[0065] Figure 8 This is a three-dimensional coordinate system constructed when a standard horizontal target is applied to a classroom scene in an embodiment of the present invention;

[0066] Figure 9 This is a spatial position diagram of the subject's eye P relative to the visual target in a three-dimensional coordinate system, as shown in this embodiment of the invention.

[0067] Figure 10 This is a horizontal perspective spatial front view (XOY plane) in an embodiment of the present invention;

[0068] Figure 11 This is a top view (XOZ plane) from a horizontal perspective in an embodiment of the present invention;

[0069] Figure 12 This is a diagram illustrating the horizontal perspective formula inference on the XOZ plane according to an embodiment of the present invention.

[0070] Figure 13 This is a vertical perspective spatial front view (XOY plane) in an embodiment of the present invention;

[0071] Figure 14 This is a vertical perspective spatial side view (XOY plane) in an embodiment of the present invention;

[0072] Figure 15 This is a vertical perspective spatial side view (YOZ plane) in an embodiment of the present invention;

[0073] Figure 16 This is a diagram illustrating the vertical perspective formula inference in the YOZ plane according to an embodiment of the present invention.

[0074] Figure 17 A diagram of the horizontal field of vision of the human eye;

[0075] Figure 18 A diagram of the vertical field of vision of the human eye;

[0076] Figure 19 This is a schematic diagram of the vision detection system based on arbitrary spatial location in an embodiment of the present invention.

[0077] In the diagram, 101 is the coordinate construction module; 102 is the position determination module; 103 is the viewing angle determination module; and 104 is the vision determination module. Detailed Implementation

[0078] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of the invention. However, those skilled in the art will understand that the invention can be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods are omitted so as not to obscure the description of the invention with unnecessary detail.

[0079] like Figure 5 As shown, a first aspect of the present invention provides a vision detection method based on arbitrary spatial location, comprising:

[0080] Step 1: Obtain the geometric center of the target and construct a three-dimensional coordinate system with the geometric center as the origin.

[0081] In this embodiment of the invention, the carrier of the visual targets can be various display devices, such as printing visual targets of different sizes on paper, ensuring that the geometric centers of each visual target overlap, and displaying them one by one, or displaying visual targets of decreasing size one by one in the same position on an electronic screen, with the geometric centers of each visual target overlapping. The application scenarios for the visual targets of this invention can be classrooms, hospitals, optical shops, or shopping malls, etc. This invention does not limit the carrier or application scenarios of the visual targets.

[0082] The visual symbols used in this embodiment of the invention can be letter symbols, number symbols, and pictorial symbols, etc., and the size of each symbol only needs to conform to national standards. This invention does not limit the form and size of the visual symbols.

[0083] Furthermore, the geometric center of the target is obtained, and a three-dimensional coordinate system is constructed with the geometric center as the origin. This embodiment of the invention uses an E-shaped letter target as an example to illustrate this step.

[0084] First of all Figure 6 The sight mark shown in (a) with its opening direction to the right is the standard horizontal sight mark. Figure 6 The upward-facing viewpoint shown in (b) is the standard vertical viewpoint.

[0085] Taking the application of a standard horizontal target in a classroom setting as an example, its geometric center is as follows: Figure 7 The origin is O, and the subject's eye is P.

[0086] Starting from point O, the horizontal direction of the standard horizontal target is the X-axis, and the direction of the target opening is the positive direction of the X-axis.

[0087] The direction perpendicular to the ground is the Y-axis, and the positive direction of the Y-axis is obtained by rotating the X-axis square counterclockwise by 90°.

[0088] With the Z-axis perpendicular to the standard viewpoint plane "E", following the right-hand screw rule, rotate from the X-axis square to the positive Y-axis direction, with the thumb pointing to the positive Z-axis direction, to obtain a three-dimensional coordinate system, as follows: Figure 8 As shown.

[0089] When constructing a three-dimensional coordinate system, this invention can use a standard horizontal or standard vertical target, or it can use a non-standard target, that is, it can also use a horizontal target with its opening direction to the left or a vertical target with its opening direction to the downward. This invention does not limit this.

[0090] Step 2: Obtain the position information of the subject's eyes in the three-dimensional coordinate system.

[0091] In this embodiment of the invention, the position information P(P) of the subject's eyes in a three-dimensional coordinate system can be obtained using methods such as sound waves or infrared rays. x ,P y ,P z ),like Figure 9 As shown. This invention does not specifically limit the method of obtaining the position information of the subject's eyes.

[0092] The subjects of this invention can be one or more. When there are multiple subjects, the efficiency of vision testing can be significantly improved without affecting the accuracy of vision testing. For example, vision testing can be performed on multiple students simultaneously in a classroom.

[0093] Step 3: Based on the subject's resolvable smallest horizontal target, smallest vertical target, and positional information, determine the subject's horizontal viewing angle relative to the smallest horizontal target and vertical viewing angle relative to the smallest vertical target; where the horizontal target is a target with its opening facing left or right, and the vertical target is a target with its opening facing up or down, specifically:

[0094] Obtain the first length between the midpoints of the left and right sides of the minimum horizontal target, and determine the subject's horizontal viewing angle relative to the minimum horizontal target based on the first length and position information.

[0095] Obtain the second length between the midpoints of the top and bottom sides of the minimum vertical target. Based on the second length and position information, determine the subject's vertical viewing angle relative to the minimum vertical target.

[0096] In this embodiment of the invention, when calculating the horizontal viewing angle, the geometric center of the smallest horizontal target is used as the origin of the coordinate system to obtain... Figure 10 The horizontal perspective spatial front view (XOY plane) and Figure 11 The horizontal viewpoint spatial top view (XOZ plane) is shown.

[0097] Furthermore, combine Figure 12 The diagram showing the derivation of the horizontal viewing angle formula on the XOZ plane yields the formula for calculating the horizontal viewing angle, as shown in equation (1):

[0098]

[0099] In the formula: ∠LPR is the horizontal viewing angle, LR is the first length between the midpoints of the left and right sides of the smallest horizontal target, PA is the distance from the subject to the XOY plane (the wall where the blackboard is located), and OP is the distance from the subject to the origin. Formula (1) is then expressed as P(P x ,P y ,P z Characterizing the expression, we obtain formula (2):

[0100]

[0101] In the formula: ∠LPR is the horizontal angle of view, LR is the first length between the midpoints of the left and right sides of the smallest horizontal target, and P x P represents the x-axis coordinate of the subject in a three-dimensional coordinate system. y P represents the y-axis coordinate of the subject in a three-dimensional coordinate system. z The z-axis coordinate of the subject in the three-dimensional coordinate system.

[0102] Furthermore, when calculating the vertical viewing angle, the geometric center of the smallest vertical target is used as the origin of the coordinate system, resulting in... Figure 13 The vertical perspective front view shown (XOY plane, actually equivalent to the vertical blackboard perspective) Figure 14 The vertical perspective side view shown (XOY plane, actually equivalent to a view perpendicular to the blackboard) and Figure 15 The vertical perspective side view (YOZ plane) is shown.

[0103] Furthermore, combine Figure 16 The diagram showing the derivation of the vertical angle formula on the YOZ plane yields the formula for calculating the vertical angle, as shown in equation (3):

[0104]

[0105] In the formula: ∠UPD is the vertical viewing angle, UD is the first length between the midpoints of the upper and lower sides of the smallest vertical target, PA is the distance from the subject to the XOY plane (the wall where the blackboard is located), and OP is the distance from the subject to the origin. Formula (3) is then expressed as P(P x ,P y ,P z Characterizing this, we obtain formula (4):

[0106]

[0107] In the formula, ∠UPD is the vertical viewing angle, UD is the first length between the midpoints of the upper and lower sides of the smallest vertical target, and P... x P represents the x-axis coordinate of the subject in a three-dimensional coordinate system. y P represents the y-axis coordinate of the subject in a three-dimensional coordinate system. z The z-axis coordinate of the subject in the three-dimensional coordinate system.

[0108] Step 4: Determine the standard visual acuity value of the subject based on the horizontal and vertical viewing angles.

[0109] One method for determining standard visual acuity values ​​according to embodiments of the present invention is as follows:

[0110] Determine the minimum values ​​of the horizontal and vertical viewing angles according to formula (5):

[0111] α=min(∠LPR,∠UPD) (5)

[0112] In the formula, ∠LPR is the horizontal viewing angle, and ∠UPD is the vertical viewing angle.

[0113] Then, the standard visual acuity value of the subject is determined using formula (6), which is characterized by logarithmic visual acuity.

[0114] LES=5-lg(α5)=5-lgα+lg5=5.699-lgα (6)

[0115] In the formula, LES is the standard visual acuity value, ∠LPR is the logarithmic visual acuity value, ∠UPD is the horizontal visual angle, and ∠UPD is the vertical visual angle.

[0116] To further improve the accuracy of the determined standard visual acuity value, this embodiment of the invention may also employ a second scheme when determining the standard visual acuity value, specifically:

[0117] Compare the horizontal and vertical visual angles; when the horizontal visual angle is smaller than the vertical visual angle, use a horizontal optotype (i.e., an optotype whose opening faces left or right), and then determine the subject's standard visual acuity value based on the horizontal visual angle of the horizontal optotype. That is, if ∠LPR < ∠UPD, then determine the subject's standard visual acuity value according to formula (7):

[0118] LES=5-lg(∠LPR5)=5-lg∠LPR+lg5=5.699-lg∠LPR (7)

[0119] When the vertical angle is less than or equal to the horizontal angle, a vertical optotype (i.e., an optotype whose opening faces upward or downward) is used. Then, the standard visual acuity value of the test subject is determined according to the vertical angle of the vertical optotype. That is, if ∠UPD≤∠LPR, the standard visual acuity value of the test subject is determined according to formula (8):

[0120] LES=5-lg(∠UPD5)=5-lg∠UPD+lg5=5.699-lg∠UPD (8)

[0121] Furthermore, since the human eye has a limited field of vision, the horizontal viewing angle in this invention is required to be less than ±60° and the vertical viewing angle is required to be less than ±30°.

[0122] The specific reasons are as follows:

[0123] The human eye's field of vision is divided into horizontal field of vision, vertical field of vision, and depth field of vision (the range at which the human eye can distinguish the distance of objects), which is called "depth of field" in the imaging field.

[0124] I. Horizontal visual field differs depending on whether it is monocular, binocular, or under conditions of eye movement, such as... Figure 17 As shown:

[0125] (1) The visual field of a single eye (without moving the eyeball or neck) is approximately 95° to the left and right, for a total of 190°;

[0126] (2) Monocular vision (moving the eyeballs while keeping the neck still) can obtain a larger field of vision, increasing by about 15° to the left and right;

[0127] (3) The visual field angle when both eyes overlap is 120°, but the comfort angle is 60°. Therefore, the embodiment of the present invention limits the horizontal visual field to less than ±60°.

[0128] II. Vertical Field of View:

[0129] The vertical field of vision of a person is approximately 60° upwards and 75° downwards, totaling 135°, with a comfortable angle of 55°. However, in order to further improve the accuracy of the determined standard visual acuity value, the vertical field of vision in this embodiment of the invention is limited to less than ±30°.

[0130] A second aspect of the present invention provides a vision detection system based on arbitrary spatial location, such as... Figure 19 As shown, it includes a coordinate construction module 101, a position determination module 102, a viewing angle determination module 103, and a vision determination module 104.

[0131] The coordinate construction module 101 is used to obtain the geometric center of the standard target and construct a three-dimensional coordinate system with the geometric center as the origin.

[0132] The position determination module 102 is used to obtain the position information of the subject's eyes in the three-dimensional coordinate system;

[0133] The viewing angle determination module 103 is used to determine the horizontal viewing angle of the subject relative to the smallest horizontal target and the vertical viewing angle relative to the smallest vertical target based on the smallest horizontal target, the smallest vertical target, and position information that the subject can distinguish; the horizontal target is a target with its opening facing left or right, and the vertical target is a target with its opening facing up or down.

[0134] The vision determination module 104 is used to determine the standard visual acuity value of the subject based on the horizontal and vertical viewing angles.

[0135] The method and system of this invention can perform vision testing at any location in space, simultaneously by one or more people, with high testing efficiency. Furthermore, the method and system of this invention have high testing accuracy, reaching the minimum resolution of the human eye, 1' to 1.5', or 1 / 60° (0.017°), which is higher than the national standard of 0.1° visual angle (5-minute recording method). The resolving power of the human eye is determined by the spacing between visual cells on the retina; therefore, there exists an observation angle at which the eye can just distinguish two lines. Measurements show that this minimum observation angle is approximately 1 to 1.5', roughly equal to the resolution of the human eye's optical system.

[0136] The method and system of the present invention do not require a fixed distance or fixed optotypes, so the test subject can undergo vision testing anywhere, such as in hospitals, optical shops, schools, shopping malls, etc., making it widely applicable and highly practical.

[0137] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A vision detection method based on arbitrary spatial location, characterized in that, include: Obtain the geometric center of the target and construct a three-dimensional coordinate system with the geometric center as the origin; Obtain the position information of the subject's eyes in the three-dimensional coordinate system; Based on the subject's resolvable minimum horizontal target, minimum vertical target, and position information, determine the subject's horizontal viewing angle relative to the minimum horizontal target and vertical viewing angle relative to the minimum vertical target; the horizontal target is a target with its opening facing left or right, and the vertical target is a target with its opening facing up or down. The standard visual acuity value of the subject is determined based on the horizontal and vertical viewing angles. Determining the subject's horizontal viewing angle relative to the minimum horizontal target and vertical viewing angle relative to the minimum vertical target specifically includes: Obtain the first length between the midpoints of the left and right sides of the minimum horizontal target, and determine the horizontal viewing angle of the subject relative to the minimum horizontal target based on the first length and the position information; Obtain the second length between the midpoints of the upper and lower sides of the minimum vertical target, and determine the vertical viewing angle of the subject relative to the minimum vertical target based on the second length and the position information.

2. The vision detection method based on arbitrary spatial location according to claim 1, characterized in that, Determining the horizontal angle of the subject relative to the minimum horizontal target specifically includes: The horizontal angle of the subject relative to the minimum horizontal target is determined according to the first formula, which is: ; In the formula: A horizontal perspective. The first length between the midpoints of the left and right sides of the minimum horizontal target is given. The subject in the three-dimensional coordinate system Axis coordinates The subject in the three-dimensional coordinate system Axis coordinates The subject in the three-dimensional coordinate system Axis coordinates.

3. The vision detection method based on arbitrary spatial location according to claim 1, characterized in that, Determining the vertical angle of the subject relative to the minimum vertical target specifically includes: The vertical angle of the subject relative to the minimum vertical target is determined according to the second formula, which is: ; In the formula, From a vertical perspective, The first length between the midpoints of the top and bottom sides of the minimum vertical target is given. The subject in the three-dimensional coordinate system Axis coordinates The subject in the three-dimensional coordinate system Axis coordinates The subject in the three-dimensional coordinate system Axis coordinates.

4. The vision detection method based on arbitrary spatial location according to any one of claims 1-3, characterized in that, Based on the horizontal and vertical viewing angles, the standard visual acuity value of the subject is determined, specifically including: The standard visual acuity value of the test subject is determined according to the third formula, which is: ; In the formula, This is the standard visual acuity value, which is a logarithmic visual acuity value. , A horizontal perspective. This is a vertical perspective.

5. The vision detection method based on arbitrary spatial location according to any one of claims 1-3, characterized in that, Based on the horizontal and vertical viewing angles, the standard visual acuity value of the subject is determined, specifically including: Compare the horizontal viewpoint and the vertical viewpoint; When the horizontal angle of view is smaller than the vertical angle of view, the standard visual acuity value of the subject is determined by using the horizontal angle of view corresponding to the minimum horizontal optotype. When the vertical angle is less than or equal to the horizontal angle, the standard visual acuity value of the subject is determined using the vertical angle corresponding to the minimum vertical optotype.

6. The vision detection method based on arbitrary spatial location according to claim 1, characterized in that, The test subject can be one or more.

7. The vision detection method based on arbitrary spatial location according to claim 1, characterized in that, The horizontal viewing angle is less than ±60°, and the vertical viewing angle is less than ±30°.

8. A vision detection system based on arbitrary spatial location, characterized in that, include: A coordinate construction module is used to obtain the geometric center of the standard target and construct a three-dimensional coordinate system with the geometric center as the origin. A position determination module, which is used to obtain the position information of the subject's eyes in the three-dimensional coordinate system; A viewing angle determination module is used to determine the horizontal viewing angle of the subject relative to the minimum horizontal visual target and the vertical viewing angle of the subject relative to the minimum vertical visual target based on the minimum horizontal visual target, the minimum vertical visual target, and the position information; the horizontal visual target is a visual target with an opening facing left or right, and the vertical visual target is a visual target with an opening facing up or down. A vision determination module is used to determine the standard visual acuity value of the subject based on the horizontal and vertical viewing angles. Determining the subject's horizontal viewing angle relative to the minimum horizontal target and vertical viewing angle relative to the minimum vertical target specifically includes: Obtain the first length between the midpoints of the left and right sides of the minimum horizontal target, and determine the horizontal viewing angle of the subject relative to the minimum horizontal target based on the first length and the position information; Obtain the second length between the midpoints of the upper and lower sides of the minimum vertical target, and determine the vertical viewing angle of the subject relative to the minimum vertical target based on the second length and the position information.

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