CN113080836B

CN113080836B - Visual detection and visual training equipment for non-central fixation

Info

Publication number: CN113080836B
Application number: CN202110344622.6A
Authority: CN
Inventors: 杜煜
Original assignee: Shanghai Qingyan Technology Co ltd
Current assignee: Shanghai Qingyan Technology Co ltd
Priority date: 2021-03-31
Filing date: 2021-03-31
Publication date: 2024-05-24
Anticipated expiration: 2041-03-31
Also published as: CN113080836A

Abstract

The invention provides a visual inspection device, which is characterized by comprising a display module; an image capturing and processing module comprising at least 2 near infrared cameras and at least 2 near infrared light sources; the center gazing eye Kappa angle calculation module calculates to obtain a Kappa angle of an A eye, wherein the Kappa angle of the A eye is an included angle between a central concave view line of a macula of the A eye and a pupil midline of the A eye; and the non-central gazing deviation angle calculation module is used for calculating to obtain the pupil midline of the B eye and the macula fovea line of the B eye, and further calculating to obtain the non-central gazing deviation angle of the B eye. Another technical scheme of the invention is to provide visual training equipment. The invention has the beneficial effects that: the visual detection and visual training equipment provided by the invention enables the detection result of non-central fixation to be objective and accurate, the visual training content to be rich, and the training state and effect to be monitored in real time.

Description

Visual detection and visual training equipment for non-central fixation

Technical Field

The invention relates to the field of ophthalmic medical equipment, in particular to visual detection and visual training equipment for non-central fixation.

Background

The human eye is a delicate optical imaging organ. When the eyes look at the foreign objects, the light rays emitted by the objects enter the eyes from the pupils of the people and are imaged on the retina. The fovea is a depression centered in the macular region of the retina, about 1.5mm to 2mm in diameter. The fovea is the most acute visual site on the retina, the macular area is central vision, and the retina outside the macular area is peripheral vision. When an object is imaged in the fovea, vision is most sensitive, and the farther the object is imaged from the fovea, the less vision is sensitive.

The use of macular foveal fixation is known as central fixation (central fixation). Some subjects have inhibited macular fovea due to strabismus or abnormal eye development, and a retinal image outside the macular fovea is used instead of the macular fovea, called non-central fixation (ECCENTRIC OR NONFOVEOLAR FIXATION). According to the location of the retinal gaze point, the non-central gaze may be divided into a parafoveal gaze (parafoveolar fixation), a paramacular gaze (parafoveal fixation), a peripheral gaze (PERIPHERALLY ECCENTRIC fixation) and a wandering gaze (WANDERING FIXATION). The traditional checking method of the fixation property is the microscopic examination, the relative position of an imaging point of retina and a central fovea of macula is 0-1 degree as central fixation, 2-3 degrees as side fovea fixation, 4-5 degrees as side macula fixation (also called as side macula fixation), and 5 degrees as peripheral fixation.

Non-central fixation imaging outside the fovea of the macula tends to result in non-central fixation amblyopia (also known as paracentral fixation amblyopia), which may also cause multiple or confusing vision to some people. Therefore, the visual detection and visual training are carried out on the non-central fixation, and the normal central fixation is rebuilt, so that the method has important clinical significance.

The conventional checking method for non-central fixation is a checking glasses checking method, the position of the non-central fixation needs subjective estimation, quantitative and accurate measurement is not easy to perform, and young children are not easy to cooperate with the checking method.

The traditional vision training method for non-central fixation is as follows: masking, afterimage therapy, red filter therapy, sea Ding Geguang brush therapy, etc. The training content is single, children are not easy to adhere to the training, and the effect of the training is not easy to monitor and evaluate in real time.

Disclosure of Invention

The purpose of the invention is that: a visual detection and visual training device is provided that may be used for non-central gaze.

In order to achieve the above object, the present invention provides a visual inspection apparatus, which sets one of two eyes as a central gazing eye, called an a eye, and the other eye as a non-central gazing eye, called a B eye, and is characterized by comprising:

A display module;

An image capturing and processing module comprising at least 2 near infrared cameras and at least 2 near infrared light sources for continuously capturing images of the eye area; the image shooting and processing module further comprises an image processing function, and the image processing function is used for carrying out image processing calculation on the shot image of the area; when an A-eye image is shot, the image shooting and processing module obtains a pupil center three-dimensional coordinate of the A-eye and a cornea reflecting point center three-dimensional coordinate of each A-eye through an image processing function; when the B eye image is shot, the image shooting and processing module obtains the center three-dimensional coordinates of the pupil of the B eye and the center three-dimensional coordinates of the reflection points of each cornea of the B eye through an image processing function; the relative positions of the image shooting and processing module and the display module are fixed and known;

The central gazing eye Kappa angle calculation module is used for defining an A-eye macular fovea line of sight as a straight line passing through the A-eye macular fovea and the A-eye pupil center, and the A-eye macular fovea line of sight intersects with the gazing position when the A-eye gazes at a foreign object; the central gazing eye Kappa angle calculation module controls the display module to display a visual target T _a which is visible by only an eye A at a designated position, and after a testee gazes at the visual target T _a, the central concave line of sight of the macula of the eye A is a straight line passing through the pupil center of the eye A and the visual target T _a; the center gazing eye Kappa angle calculation module calculates the pupil center line of the eye A by calculating the three-dimensional coordinates of the pupil center of the eye A and the three-dimensional coordinates of the center of each cornea reflecting point of the eye A, so as to calculate the Kappa angle of the eye A, wherein the Kappa angle of the eye A is the included angle between the central concave line of sight of the macula of the eye A and the pupil center line of the eye A;

The non-central gazing deviation angle calculation module is used for defining the B eye abnormal sight line as a straight line passing through the B eye pupil center and the gazing position of the B eye gazing at the foreign object; defining a B-eye macular fovea line of sight as a straight line passing through the B-eye macular fovea and the B-eye pupil center; the non-central fixation deviation angle calculation module controls the display module to display a visual target T _b which can be seen by only the B eye at a designated position, and after the testee fixates at the visual target T _b, the abnormal line of sight of the B eye is a straight line passing through the pupil center of the B eye and the visual target T _b; the non-central gaze deviation angle calculation module calculates a pupil center line of the B eye and a macula fovea line of the B eye by calculating the three-dimensional coordinates of the pupil center of the B eye and the three-dimensional coordinates of the central reflecting points of each cornea of the B eye, and further calculates a non-central gaze deviation angle of the B eye, wherein the non-central gaze deviation angle of the B eye is an included angle between an abnormal line of the B eye and the macula fovea line of the B eye, and the non-central gaze deviation angle of the B eye is an included angle between the abnormal line of the B eye and the macula fovea line of the B eye, wherein the non-central gaze deviation angle comprises the three-dimensional coordinates of the pupil center of the B eye and the macula fovea line of the B eye:

the non-central fixation deviation angle calculation module obtains the central concave vision of the macula of the B eye in the following way;

According to the principle of physiological symmetry of the left eye and the right eye, the included angle between the central concave view line of the macula of the B eye and the pupil midline of the B eye is equal to the Kappa angle of the A eye, the included angle direction is in mirror symmetry with the median sagittal plane of a person, and therefore the non-central gaze deviation angle calculation module calculates the central concave view line of the macula of the B eye based on the Kappa angle of the A eye obtained by the central gaze eye Kappa angle calculation module.

Preferably, the system also comprises a judging module, which is used for calculating the included angle between the central concave line of sight of the macula of the B eye and the abnormal line of sight of the B eye when the single eye of the B eye gazes at the visual target; and when the included angle between the central concave view line of the macula of the eye B and the abnormal view line of the eye B is a stable value within a period of time, the judging module judges that the eye B is stable non-central fixation.

Preferably, the system also comprises a judging module, which is used for calculating the included angle between the central concave line of sight of the macula of the B eye and the abnormal line of sight of the B eye when the single eye of the B eye gazes at the visual target; and when the included angle between the central concave view line of the macula of the eye B and the abnormal view line of the eye B is an unstable value within a period of time, the judging module judges that the eye B is the wandering non-central gazing.

Another aspect of the present invention provides a visual inspection apparatus for setting one of two eyes as a non-central gazing eye, referred to as B eye, which is known as a stable non-central gazing, comprising:

the display module is used for displaying the content which can be seen by only the B eye, and the content displayed by the display module cannot be seen by the other eye;

the image shooting and processing module comprises at least one camera and can continuously shoot images containing the B eye area;

The eye movement point calculation module is used for obtaining a calibration function of the B eye through monocular calibration of the B eye, and further calculating to obtain a B eye movement point coordinate according to the B eye image and the B eye calibration function, wherein when monocular calibration is carried out on the B eye, the eye movement point calculation module controls the display module to display a calibration visual target which can be seen by the B eye only;

a non-central gaze deviation angle calculation module:

after the calibration of the B eye is finished, the non-central fixation deviation angle calculation module controls the display module to display a first visual target which is visible only by the B eye; after the person to be checked looks at the first sighting mark, the non-central looking deviation angle calculation module obtains a first sight line, and a connecting line between the pupil center of the B eye and the first sighting mark is defined as the first sight line;

the non-central gaze deviation angle calculation module controls the display module to display the second visual target at a variable position within a 1-10-degree radius visual angle around the first visual target; the subject responds to whether the second optotype can be seen at the same time while looking at the first optotype; when the second visual target can be seen most clearly, the non-central gaze deviation angle calculation module obtains a second visual line, and the second visual line is defined as a connecting line between the pupil center of the B eye and the display position of the second visual target at the moment;

The non-central gaze deviation angle calculation module calculates a non-central gaze deviation angle based on the first sight line and the second sight line, wherein the non-central gaze deviation angle is an included angle between the first sight line and the second sight line; meanwhile, the eye movement point calculation module monitors the eye movement point of the eye B of the testee in real time, if the eye movement point of the eye B leaves the position displayed by the first visual target, the position of the first visual target is moved in real time to be equal to the position of the eye movement point of the eye B, and the display position of the second visual target is moved to keep the relative position of the second visual target and the first visual target unchanged; or the test result is invalid during the period that the eye movement point of the B eye leaves the first sighting target position, and the test is conducted again.

the visual evoked potential calculation module is used for wearing a visual evoked potential device on the head of the detected person and recording the visual evoked potential of the detected person;

a non-central gaze deviation angle calculation module:

After calibration is finished, the non-central gaze deviation angle calculation module controls the display module to display a visual target which is visible to only the B eye, the non-central gaze deviation angle calculation module obtains a first sight line after the testee gazes at the visual target, and the first sight line is defined as a connecting line of the pupil center of the B eye and the visual target as the first sight line;

The non-central gazing deviation angle calculation module controls the display module to display periodic flickering light spots at variable positions in the visual angles from 1-10 degrees of radius around the optotype; the visual evoked potential calculation module records visual evoked potential and corresponds to the position displayed by the flickering light spot; recording the display position of the scintillation light spot when the visual evoked potential amplitude is maximum, and obtaining a second sight line by the non-central gaze deviation angle calculation module by using the recorded display position of the scintillation light spot, wherein the second sight line is defined as a connecting line between the pupil center of the B eye and the display position of the scintillation light spot at the moment;

The non-central gaze deviation angle calculation module calculates a non-central gaze deviation angle based on the first sight line and the second sight line, wherein the non-central gaze deviation angle is an included angle between the first sight line and the second sight line; meanwhile, the eye movement point calculation module monitors the eye movement point of the tested eye B in real time, if the eye movement point of the eye B leaves the position of the visual target, the position of the visual target is moved in real time to be equal to the position of the eye movement point of the eye B, and the display position of the flickering light spot is moved to keep the display position of the flickering light spot unchanged with the relative position of the visual target; or the test result is invalid when the eye movement point of the eye B is set to leave the position of the sighting target, and the test is conducted again.

Another aspect of the present invention provides a vision training apparatus, which sets one of two eyes as a non-central gazing eye, referred to as a B eye, wherein the B eye is known to be a stable non-central gazing and a non-central gazing deviation angle is known, and is characterized by comprising:

The macula lutea fovea line of sight intersection calculation module defines the abnormal line of sight of the B eye as a straight line passing through the pupil center of the B eye and the eye movement point of the B eye; the macula lutea fovea sight intersection point calculating module can calculate to obtain a macula lutea fovea sight line of the B eye according to the abnormal sight line of the B eye and the non-central fixation deviation angle, and further calculate to obtain a macula lutea fovea sight line intersection point of the B eye, wherein the macula lutea fovea sight line intersection point of the B eye is an intersection point of the macula lutea fovea sight line of the B eye and a display plane;

Training module: during vision training, the training module controls the display module to display clear images near the B-eye macula fovea line intersection point obtained by the macula fovea line intersection point calculation module, and does not display images or displays suppressed images at the position of the B-eye macula fovea line intersection point.

Preferably, in the training module, during vision training, the training module controls the display module to display a clear image near the intersection point of the central concave vision line of the macula of the B eye, and when the intersection point of the central concave vision line of the macula of the B eye moves, the position of the image display moves along with the movement of the intersection point of the central concave vision line of the macula of the B eye; and displaying no image at other positions of the display plane of the display module.

Preferably, in the training module, during vision training, the image display range does not exceed a circular range with the center concave line of sight intersection of the macula lutea of the B eye as the center of a circle, and the radius is less than or equal to 2 degrees of visual angle.

Preferably, in the training module, during vision training, the display module displays a clear image near the intersection of the central concave view lines of the macula of the B-eye, displays a suppressed image in a region far from the intersection of the central concave view lines of the macula of the B-eye, and the position of the image display does not move along with the movement of the intersection of the central concave view lines of the macula of the B-eye.

Preferably, in the training module, when the training module controls the display module to display the image, the range of displaying the clear image does not exceed the circular range with the center concave line of sight intersection of the macula lutea of the B eye as the center of a circle, and the radius is less than or equal to 2 degrees of visual angle.

The training module is used for controlling the display module to display an image P ₁ at the intersection point of the B eye abnormal sight line and the display plane and to display an image P ₂ at the intersection point of the B eye macula fovea sight line and the display plane during vision training; under the condition of keeping the position of the eye movement point of the eye B unchanged, the training module gradually improves the degree of depression of the image P ₁ and performs vision training.

Preferably, in the training module, the range displayed by the image P ₁ and the image P ₂ does not exceed the circular range with the radius equal to or less than 2 ° viewing angle.

Another aspect of the present invention provides a vision training apparatus, in which one of two eyes is a central gazing eye, called an a eye, and the other eye is a non-central gazing eye, called a B eye, known as Kappa angle of the a eye, characterized by comprising:

the display module displays content which is visible only by the B eye and cannot be seen by the other eye;

The image shooting and processing module comprises at least 2 near infrared cameras and at least 2 near infrared light sources and can continuously shoot images of the B eye; the system comprises an image processing function, wherein the image processing function can be used for carrying out image processing calculation on the shot image of the region to obtain a three-dimensional coordinate of the pupil center of the eye B and a three-dimensional coordinate of the center of each cornea reflection point of the eye B, and the relative positions of an image shooting and processing module and a display module are known;

the macula lutea fovea line intersection point calculating module calculates a pupil center line of the B eye and macula lutea fovea line of the B eye by calculating the three-dimensional coordinates of the pupil center of the B eye and the three-dimensional coordinates of the center of each cornea reflecting point of the B eye, and further calculates to obtain a macula lutea fovea line intersection point of the B eye, wherein the macula lutea fovea line intersection point of the B eye is an intersection point of the macula lutea fovea line of the B eye and a display plane;

The macula fovea line intersection point calculating module obtains macula fovea line of the B eye in the following manner:

According to the principle of physiological symmetry of the left eye and the right eye, the included angle between the macula fovea line of the B eye and the pupil midline of the B eye is equal to the Kappa angle of the A eye, the included angle direction is in mirror symmetry with the median sagittal plane of the person, and therefore the macula fovea line intersection point calculating module calculates the macula fovea line of the B eye based on the Kappa angle of the A eye and the pupil midline of the B eye;

And the training module is used for displaying clear images near the central concave vision intersection point of the macula lutea of the B eye and displaying no images or suppressed images in other areas during vision training.

Preferably, the image is displayed at the B-eye macular fovea line intersection, and when the B-eye macular fovea line intersection moves, the position of the image display moves along with the B-eye macular fovea line intersection; no image is displayed at other positions of the display plane.

Preferably, in the training module, when the image is displayed on the display module, the range of displaying the clear image does not exceed the circular range with the center concave line of sight intersection of the macula lutea of the B eye as the center of a circle, and the radius is less than or equal to 2 degrees of visual angle.

Another aspect of the present invention provides a vision training apparatus, which sets one of two eyes as a central gazing eye, called an a eye, and the other eye as a non-central gazing eye, called a B eye, wherein the B eye is known to be a stable non-central gazing and the non-central gazing deviation angle is known, and the vision training apparatus is characterized by comprising:

a display module which can display an image visible only to a left eye and can display an image visible only to a right eye;

the image shooting and processing module comprises at least one camera and can continuously shoot images containing an A eye area and a B eye area;

the eye movement point calculation module is used for calculating and obtaining eye movement point coordinates of an eye A and eye movement point coordinates of an eye B, wherein:

When the eye movement point coordinate of the A eye is calculated, the eye movement point calculation module is used for obtaining a calibration function of the A eye through monocular calibration of the A eye, and further calculating the eye movement point coordinate of the A eye according to the image of the A eye and the calibration function of the A eye, wherein the eye movement point coordinate of the A eye is an intersection point between a macula fovea line of the A eye and a display plane, and when the monocular calibration is carried out on the A eye, the eye movement point calculation module controls the display module to display a calibration visual target which can be seen by the A eye only;

When the eye movement point coordinates of the B eye are calculated, the eye movement point calculation module is used for obtaining a calibration function of the B eye through monocular calibration of the B eye, and further calculating the eye movement point coordinates of the B eye according to the B eye image and the B eye calibration function, wherein when the monocular calibration is carried out on the B eye, the eye movement point calculation module controls the display module to display a calibration visual target which can be seen by the B eye only;

The macula lutea fovea line of sight intersection calculation module defines the abnormal line of sight of the B eye as a straight line passing through the pupil center of the B eye and the eye movement point of the B eye; the macula lutea fovea sight intersection point calculating module calculates a macula lutea fovea sight line of the B eye according to the abnormal sight line of the B eye and the non-central gaze deviation angle, and further calculates a macula lutea fovea sight line intersection point of the B eye, wherein the macula lutea fovea sight line intersection point of the B eye is an intersection point of the macula lutea fovea sight line of the B eye and a display plane;

The training module is used for controlling the display module to display an image P _A which is visible only by the A eye during vision training; after the trainer looks at the image P _A, the training module controls the display module to display an image P _B only visible to the B eye at the intersection point of the B eye macula fovea sight line and the display module; the training module then controls the display module to keep images P _A and P _B displayed simultaneously for visual training.

Preferably, in the training module, during visual training, the image P _A and the image P _B are complementary images, and need to be seen at the same time to form a complete image.

Preferably, in the training module, during vision training, the image P _A and the image P _B are images with the same shape and size.

Preferably, in the training module, during vision training, the image P _A and the image P _B are stereoscopic images with binocular parallax.

Preferably, in the training module, the range displayed by the image P _A and the image P _B does not exceed the circular range with the radius equal to or less than 2 ° viewing angle.

Preferably, when the B-eye macular fovea line intersection is changed, the position of the image P _B is moved along with it, always at the position of the B-eye macular fovea line intersection.

The image shooting and processing module comprises at least 2 near infrared cameras and at least 2 near infrared light sources and can continuously shoot images of the B eye; the image shooting and processing module further comprises an image processing function, and performs image processing calculation on the shot image of the region through the image processing function to obtain a B-eye pupil center three-dimensional coordinate and a B-eye cornea reflecting point center three-dimensional coordinate;

The macula fovea line of sight calculation module is used for calculating the pupil center three-dimensional coordinates of the B eye and the center three-dimensional coordinates of each cornea reflecting point of the B eye to obtain the pupil center line of the B eye and the macula fovea line of sight of the B eye;

The macular fovea line of sight calculation module obtains the macular fovea line of sight of the B eye in the following manner:

According to the principle of physiological symmetry of the left eye and the right eye, the included angle between the macula fovea line of the B eye and the pupil midline of the B eye is equal to the Kappa angle of the A eye, and the included angle direction is in mirror symmetry with the median sagittal plane of the person, so that the macula fovea line of the B eye is calculated by the macula fovea line calculation module based on the Kappa angle of the A eye and the pupil midline of the B eye;

The liquid crystal shielding module is a liquid crystal lens positioned in the B eye view range, controls the liquid crystal lens to be transparent in a certain range at and near the intersection point of the B eye macula fovea sight line and the liquid crystal lens, is opaque in other areas, performs vision training, can change in real time along with the change of the macula fovea sight line, and is always positioned at the intersection point of the B eye macula fovea sight line and the liquid crystal lens; the relative positions of the liquid crystal shielding module and the image shooting and processing module are fixed and known.

Preferably, in the liquid crystal shielding module, the transparent range of the liquid crystal shielding module is not more than a circular range with the center concave line of sight intersection of the macula lutea of the B eye as the center of a circle, and the radius is less than or equal to 2 degrees of visual angle.

Preferably, the vision training device may be integrated into a headset, which is a pair of glasses, VR device, or AR device.

The invention has the beneficial effects that: the visual detection and visual training equipment provided by the invention enables the detection result of non-central fixation to be objective and accurate, the visual training content to be rich, and the training state and effect to be monitored in real time.

Drawings

FIG. 1 (a) is a schematic view of a foveal line of sight of the macula in the right eye in embodiment one; FIG. 1 (b) is a schematic view of the right eye Kappa angle; FIG. 1 (c) is a schematic view of an abnormal line of sight for the left eye; FIG. 1 (d) is a schematic illustration of the calculation of left eye macular foveal line of sight from left eye pupil midline;

FIG. 2 is a schematic diagram showing the positions of the components of the apparatus in the first embodiment;

FIG. 3 is a schematic diagram showing the relative positional relationship of a display, 2 cameras, 2 light sources, and left and right eyes in the first embodiment;

Fig. 4 is a schematic diagram of three-dimensional spatial positioning principle of the pupil center by the dual camera system in the first embodiment;

FIG. 5 is a schematic diagram of pupil center line calculation in the first embodiment;

FIG. 6 is a schematic diagram of a cursor display position in the second embodiment;

fig. 7 is a schematic diagram of a calculation method of the central concave line-of-sight intersection of yellow spots in the fourth embodiment.

Detailed Description

The application will be further illustrated with reference to specific examples. It is to be understood that these examples are illustrative of the present application and are not intended to limit the scope of the present application. Furthermore, it should be understood that various changes and modifications can be made by one skilled in the art after reading the teachings of the present application, and such equivalents are intended to fall within the scope of the application as defined in the appended claims.

Example 1

For a normal central fixation eye, when the external object is fixed, the light rays emitted by the external object pass through the pupil center and are imaged in the macula fovea. In the invention, the central gazing eye 'macular fovea line of sight' is defined as a straight line passing through the central gazing eye macular fovea and the pupil center, and the central gazing eye 'macular fovea line of sight' extends to the outside of eyeballs and intersects with the gazing position when the central gazing eye gazes at the foreign object. For a normal central fixation eye, the "foveal line of sight" is the visual axis.

For a non-central fixation eye, the foreign object cannot be imaged in the fovea of the macula when looking at the foreign object. The non-central gaze eye 'macular fovea line of sight' is defined as a straight line passing through the non-central gaze eye macular fovea and the pupil center, and extends to the outside of the eyeball so as not to intersect with the position gazed at when gazing at the foreign object.

For example: one subject, right eye, was a central gaze and left eye was a non-central gaze.

As shown in fig. 1 (a), since the right eye thereof is a central gaze, when the right eye is used to gaze the optotype T _a on the display module, a straight line passing through the right eye gaze point (the position of the optotype T _a) and the right eye pupil center P _r intersect with the right eye retina at the macular fovea (the position of M _r).

As shown in fig. 1 (b), the dashed line is the pupil midline of the right eye of the subject. The pupil midline is the axis of symmetry of the human eye, and the macula fovea line of vision and the pupil midline of most people do not coincide exactly, and there is an included angle, which is called Kappa angle. The Kappa angle alpha of the right eye of the subject is the included angle between the central concave line of sight of the macula of the right eye and the pupil midline of the right eye.

As shown in fig. 1 (c), when the left eye of the subject is a non-central gaze and the left eye is a monocular gaze at the optotype T _b on the display module, the intersection point between the straight line passing through the left eye gaze point (the position of the optotype T _b) and the left eye aperture center P _l and the left eye retina is Y _l, and is not located at the position of the left eye macular fovea M _l. In the present invention we define an "abnormal line of sight" of an off-center gaze eye as a straight line passing through the center of the aperture of the off-center gaze eye and the location at which the eye gazes when looking at a foreign object. The imaging point of the non-central gaze eye "abnormal line of sight" on the retina is the "abnormal retinal imaging point". In fig. 1 (c), the line connecting the three points T _b、P_l、Y_l is the abnormal line of sight of the left eye. Meanwhile, the left eye macular fovea line of sight, namely a straight line passing through the left eye macular fovea and the center of the left eye pupil, and the display module intersect at a point C _l.

According to the principle of physiological symmetry of the left eye and the right eye, the included angle beta between the macula fovea line of the left eye and the pupil midline of the left eye is equal to the Kappa angle alpha of the right eye, and the included angle direction is mirror symmetry with the median sagittal plane of the human body (the human body is bilateral symmetry with the median sagittal plane). Accordingly, as shown in fig. 1d, when the pupil center line of the left eye of the subject is known (broken line in the figure), and the Kappa angle and direction of the right eye of the subject are also known, and the median sagittal plane of the head is also known, the angle β between the macular fovea line of the left eye and the pupil center line of the left eye is known, and the macular fovea line of the left eye can be obtained. If the relative positions of the left eye and the display module are known, the position of the point C _l of intersection of the left eye macular fovea line and the display module is also known.

As shown in fig. 2, the visual inspection apparatus provided in this embodiment includes a display module, an image capturing and processing module, a central gaze eye Kappa angle calculation module, and a non-central gaze deviation angle calculation module. Wherein the display module is a display 1. The system also comprises an electronic computer 2, and an image processing algorithm of the image shooting and processing module, a central gazing eye Kappa angle calculating module and an off-central gazing deviation angle calculating module are all programs running on the electronic computer 2. In addition, the embodiment further includes a judging module, which can judge the type of the non-central fixation, and the judging module is also a program running on the electronic computer 2. The present embodiment further comprises a head fixation support 3.

In this embodiment, the image capturing and processing module includes 2 near infrared cameras, namely a left camera and a right camera, and further includes 2 near infrared LED point light sources with a light emission wavelength of 850nm, namely a left light source and a right light source, which are located outside the near infrared cameras. The image shooting and processing module is positioned below the display 1, and the camera, the light source and the like are arranged in the shell. Each eye can be photographed by 2 near infrared cameras in the image photographing and processing module. The relative positions between the 2 near infrared cameras, the 2 near infrared light sources and the display 1 are fixed and known. The relative positional relationship of the display 1, the left camera 4-1, the right camera 4-2, the left light source 7-1, the right light source 7-2, the left eye 5, and the right eye 6 in the image capturing and processing module is shown in fig. 3.

The specific steps of the operation of the equipment are as follows:

The subject sits in front of the device with eyes facing the display 1, and the chin of the subject is placed on the head fixing support 3 so that the heights of the left and right eyes are the same and the distances between the left and right eyes and the display 1 are the same. Two near infrared cameras 4-1, 4-2 in the image capture and processing module can capture images containing the eye region.

(II) calculating central gaze eye macula fovea line of sight

As shown in fig. 4, the optotype T _a is displayed on the display 1, and the optotype T _a is a small dot and is located in the center of the display 1.

In this step, only the right eye of the central gaze eye can see the optotype T _a. The way to make the optotype visible only to a single eye may be one of the following ways: (1) shielding the other eye with an eye shield; (2) Using a polarized display while the subject wears polarized glasses; (3) Displaying an image visible only to a single eye using a naked eye 3D display; (4) Using a stereoscopic shutter display while the subject wears shutter glasses; (5) The subject wears glasses such as red-green glasses with lenses of different colors for both eyes, and the display 1 displays an image composed of only the colors visible to one eye, accordingly.

The present embodiment uses an eye shield to shield the left eye so that only the right eye sees the optotype T _a, leaving the subject to look at the optotype T _a. The binocular camera system formed by the left camera 4-1 and the right camera 4-2 can calculate three-dimensional space coordinates based on parallax information of the same object. The three-dimensional space coordinate P _r (x, y, z) of the pupil center P _r of the right eye is calculated by:

As shown in fig. 4, the three-dimensional space coordinates take the optical center E of the left camera 4-1 as the origin, the line where the line EI connecting the optical center of the left camera 4-1 to the optical center of the right camera 4-2 is located is the X-axis, the line where the optical axis EH of the left camera 4-1 is located is the Z-axis, and the Y-axis is perpendicular to the XZ plane (not shown in this figure).

The distance between the left camera 4-1 and the right camera 4-2 is T, F is the center of the imaging plane of the left camera 4-1, and J is the center of the imaging plane of the right camera 4-2. The imaging point of pupil center P _r on left camera 4-1 is G and the imaging point on right camera 4-2 is K. Because the imaging plane dimensions of the camera are known, the X-axis distance of a certain imaging point from the center of the imaging plane is easy to calculate. The distance between the G point and the F point on the projection in the X axis direction is GF, and the distance between the K point and the J point on the projection in the X axis direction is JK.

Let ef=ij=f.

Equation ① and equation ② are derived from the similar triangle principle as follows:

Since equations ① and ② have only two unknowns, x and z, the other values GF, JK, f, T are known, and so can be solved:

similarly, the Y coordinate of the pupil center P _r can be obtained from the distance (Δy) between the imaging point of the pupil center P _r and the center of the imaging plane in the Y-axis direction:

Thus, the three-dimensional coordinates of the pupil center P _r are calculated.

Because the relative positions of the left camera and the right camera and the display are fixed, namely the three-dimensional space coordinates of the sighting target T _a are known, the three-dimensional space connecting line of the T _a and the pupil center P _r of the right eye can be determined to be the straight line of the concave line of sight of the macular of the right eye.

(III) the center gaze eye Kappa angle calculation Module calculates the pupil midline of the Right eye

The outer side of the pupil has a spherical cornea surface. The external surface of the cornea of the human eye is regarded as a convex mirror, and a virtual image is formed on the other side of the convex mirror by reflecting the point light source through the convex mirror. Based on the principle of optical imaging it is known that the position of the virtual image is determined by the position of the light source and the convex mirror, independently of the position of the observer (i.e. independently of the position of the camera). In addition, a space straight line formed by connecting the point light source and the virtual image passes through the sphere center of the sphere where the convex mirror is positioned.

As shown in fig. 5, the right eye of the subject is focused on the optotype T _a, based on the optical principle of the convex mirror reflection imaging of the point light source and the binocular vision principle, the three-dimensional space positions of the two near infrared point light sources are set to be R ₁ and R ₂, and the line connecting the three-dimensional space positions of the two near infrared reflection point virtual images on the outer surface of the cornea to be R ₁ ' and R ₂′.R₁-R₁ ' and the line connecting the R ₂-R₂ ' can be calculated to intersect at the spherical center O _c of the spherical surface on which the outer surface of the cornea is located. In addition, three-dimensional coordinates of the pupil center P _r have been measured in the previous step. The line connecting P _r and O _c is the right eye pupillary midline.

(IV) the center gaze eye Kappa Angle calculation Module calculates the Kappa Angle for the Right eye

And calculating the included angle between the central concave line of sight of the macula of the right eye and the central line of the pupil of the right eye to obtain the angle of the Kappa angle of the right eye. In this example, the right eye macular fovea line of sight is on the anterior side of the right eye pupil midline (relative position outside the eyeball) at an included angle of 2 °, i.e., a right eye Kappa angle of 2 °.

(V) the non-central gaze deviation angle calculation module calculates the non-central gaze deviation angle of the left eye

The right eye is shielded, the left eye is exposed, and the left eye is a non-central gazing eye. The display 1 displays the optotype T _b, where only the left eye can see the optotype T _b, in this embodiment the optotype T _b is a small dot in the center of the display 1. Let the person's left eye watch the sighting target T _b, can survey the three-dimensional space coordinate at left eye pupil center through binocular camera, obtain the unusual sight of left eye through calculating the line at sighting target T _b and left eye pupil center.

The pupillary midline of the left eye can be calculated by a method similar to that for the right eye.

According to the principle of physiological symmetry of the left eye and the right eye, the included angle between the macula fovea line of the left eye and the pupil midline of the left eye is equal to the Kappa angle of the right eye, and the included angle direction is in mirror symmetry with the median sagittal plane of the human body. In this embodiment, since the heights of the left and right eyes of the subject are the same and the distances between the left and right eyes and the display are the same, the median sagittal plane is perpendicular to the ground and perpendicular to the two-eye connecting line, and the angle of the left eye macular fovea line is 2 ° on the nose side of the left eye pupil midline (the relative position of the outside of the eyeball).

And then calculating the included angle between the abnormal sight line of the left eye and the central concave sight line of the macula of the left eye, so as to obtain the non-central gazing deviation angle of the left eye. For example, in the present embodiment, the temporal side of the left eye pupil midline (the relative position outside the eyeball) of the left eye abnormal line of sight is measured, and the included angle is 3 °, so in the present embodiment, the non-central gaze deviation angle of the subject's left eye is 2 ° +3+=5°, and the direction is the temporal side of the left eye macula fovea line of sight (the relative position outside the eyeball). Inside the eyeball, the abnormal retinal imaging point of the left eye is at a position 5 DEG on the central concave nose side of the macula of the left eye.

(Six) judgment of non-center gaze type

The left eye of the subject is allowed to gaze on the optotype T _b for a period of time, in this example 10 seconds. During this time, the non-central gaze deviation angle of the left eye is continuously recorded.

If the non-central gazing deviation angle is a stable value, judging that the left eye non-central gazing type is stable non-central gazing. When a stable non-central fixation means that the eye is fixation to a fixed position of the optotype, the imaging point of the optotype on the retina is a fixed point, but because this point is not on the fovea of the macula, it is called an abnormal retinal imaging point.

If the non-central gazing deviation angle is an unstable value, judging that the left eye non-central gazing type is the walk-in non-central gazing. When the wandering non-center gaze represents that the eye gazes at a fixed position, the imaging point of the optotype on the retina cannot be stabilized at a fixed point.

Example two

A subject is known to have a non-central gaze at his left eye and has qualitatively detected by conventional means (e.g. a scope, etc.) that the relative positions of the abnormal retinal imaging point and the fovea of the left eye are fixed, i.e. the "stable non-central gaze" referred to in example one. However, the traditional methods such as a shadow mask and the like are not easy to accurately and quantitatively judge the non-central fixation deviation angle. The vision detection device disclosed by the embodiment can accurately and quantitatively detect the non-central gazing deviation angle.

A visual inspection device comprises a display module, an image shooting and processing module, an eye movement point calculating module and a non-central gazing deviation angle calculating module. The system also comprises an electronic computer, wherein an image processing algorithm of the image shooting and processing module, an eye movement point calculating module and a non-central gazing deviation angle calculating module are all programs running on the electronic computer. In addition, the apparatus comprises a head fixation device on which the chin of the subject is placed, the distance between the head fixation device and the display module being fixed and known, and thus the distance between the subject's eyes and the display being fixed and known.

The display module is a display, and the displayed content can be seen only by the left eye and can not be seen by the right eye. The method can be realized by shielding the right eye with an eyeshade or by a polarized display, a naked eye 3D display and the like in the first embodiment.

The image shooting and processing module comprises at least one camera and can continuously shoot images containing a left eye area. In this embodiment, the image capturing and processing module includes 1 near infrared camera and 2 near infrared point light sources with light emitting wavelength of 850nm, the 2 near infrared light sources are located at two sides of the near infrared camera, and the near infrared camera and the near infrared light sources are placed in a housing of the image capturing and processing module. The relative positions of the image capture and processing module and the display are fixed and known.

The specific steps of the operation of the equipment are as follows:

The subject sits in front of the apparatus, places the chin on the head-mounted support, with the eyes facing the display and the eyes being sixty centimeters from the display. The near infrared camera in the image shooting and processing module continuously shoots images containing the left eye region, and calculates the pupil center and the cornea reflecting point center of the left eye in real time (the average coordinates of the two cornea reflecting points are taken as the cornea reflecting point center), so as to obtain the pupil cornea vector of the left eye.

The second eye movement point calculation module calculates eye movement points

In the embodiment, a single camera system is used, and a mapping relation between pupil cornea vector (two-dimensional) and display plane eye movement point coordinates (two-dimensional) in a shot image, namely a calibration function, is obtained through multi-point calibration.

Sequentially displaying calibration optotypes at N different positions on a display, wherein N is more than or equal to 2 and less than or equal to 9; substituting pupil cornea vector and calibration sighting target coordinates into a calibration mapping function equation set when the left eye looks at the calibration sighting target, and obtaining a left eye calibration function after solving the left eye calibration mapping function coefficients. In this embodiment, taking a 9-point calibration as an example, the calibration optotype is a point at 9 positions in the center, left, right, up, down, up-left, up-right, down-left, and down-right of the display, and the positions of the 9 points are known and determined. The 9-point calibration procedure for the left eye is as follows:

Let x _s be the abscissa of the eye movement point on the display plane, and y _s be the ordinate of the eye movement point on the display plane; x _e is the value of the pupil cornea vector in the horizontal direction, y _e is the value of the pupil cornea vector in the vertical direction, and the pupil cornea vector is obtained from the camera image in pixels.

The following mapping function ① is used:

a₀、a₁、a₂、a₃、a₄、a₅、b₀、b₁、b₂、b₃、b₄、b₅ These 12 values are not known prior to calibration. The first stage of calibration is the process of solving the 12 unknowns.

Since the coordinates (x_s1,y_s1)、(x_s2,y_s2)、(x_s3,y_s3)、(x_s4,y_s4)、(x_s5,y_s5)、(x_s6,y_s6)、(x_s7,y_s7)、(x_s8,y_s8)、(x_s9,y_s9) of the 9 calibration targets on the display plane are known; the pupil cornea vector of the 9 calibration targets can be calculated by the image shooting and processing module and is (x_e1,y_e1)、(x_e2,y_e2)、(x_e3,y_e3)、(x_e4,y_e4)、(x_e5,y_e5)、(x_e6,y_e6)、(x_e7,y_e7)、(x_e8,y_e8)、(x_e9,y_e9). to be substituted into the mapping function ① respectively, so that an equation set ② consisting of the following 18 equations can be obtained:

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because the equation number is larger than the number of unknown variables, the least square solution is needed to be calculated according to the least square solution overdetermined equation set a₀、a₁、a₂、a₃、a₄、a₅、b₀、b₁、b₂、b₃、b₄、b₅.

Because a₀、a₁、a₂、a₃、a₄、a₅、b₀、b₁、b₂、b₃、b₄、b₅ are all solved into known values, the horizontal direction value x _e of the pupil cornea vector and the vertical direction value y _e of the pupil cornea vector obtained by the image shooting and processing module are substituted into the mapping function ①, and the abscissa x _s of the eye movement point on the display plane and the ordinate y _s of the eye movement point on the display plane can be obtained.

After the steps are used for calibration, the calibration function of the left eye is obtained. And substituting the left eye pupil cornea vector obtained by the image shooting and processing module into a left eye calibration mapping function by the eye movement point calculation module, so that the eye movement point coordinates of the left eye can be calculated.

(III) the non-central gaze deviation angle calculation module calculates the non-central gaze deviation angle of the left eye

After the left eye single eye calibration is finished, the display displays a first visual target at the central position of the display, and displays a second visual target at a position which can be changed within a 1-10-degree radius visual angle around the first visual target, wherein the content, the size and the resolution of the second visual target are settable. In this embodiment, the first optotype is a "+" character and the second optotype is an "E" character with a1 ° viewing angle having a random opening direction. In this embodiment, the second optotype appears at a variable position within the angle of view of 1 ° radius to 10 ° radius around the first optotype, and on grid points at every 1 ° interval in the longitudinal direction and the transverse direction, the second optotype may be displayed sequentially in sequential positions or random positions, and all the position points that the second optotype may display are as shown in fig. 6 ("+" characters in the middle of circles are positions displayed by the first optotype). In this embodiment, the positions of the two times are not repeated, and the positions are sequentially displayed from left to right and from top to bottom. The person to be examined needs to watch the first sighting mark with the left eye, and the connecting line of the pupil center of the left eye and the first sighting mark is the first sight line; the subject responds to whether the second visual target can be seen at the same time while looking at the first visual target, and the response mode is any one mode of oral report, action gesture, key press, mouse operation and the like. In this embodiment, the subject verbally reports the opening direction of the "E" word, if the subject cannot see clearly, the subject is told to see clearly, the result is input into the computer in real time through the keyboard for storage, and the stored result corresponds to the position where the "E" word appears.

Thus, after the 'E' character with random opening direction of the second optotype appears once at all positions of grid points, the macula fovea area is the area with most sensitive vision, and although the macula fovea vision of a testee can be inhibited to a certain extent due to strabismus and the like, the macula fovea area is still likely to be the area with better vision around the abnormal retina imaging point corresponding to the abnormal vision. And displaying a second visual target in a range from a radius of 1 DEG to a radius of 10 DEG around the first visual target, if a region with obviously best vision relative to other regions exists, judging that the connecting line between the display position of the second visual target and the pupil center is a macula fovea line of sight, imaging the second visual target at the macula fovea position, and the connecting line between the pupil center of the left eye and the display position of the second visual target is a line of sight II, wherein the non-central gaze deviation angle is the included angle between the line of sight I and the line of sight II. For example, in the present embodiment, after the end of the display at all grid points, the second optotype "E" character subject displayed at the position of 5 ° viewing angle on the right side of the first optotype is seen most clearly, and can see the opening direction of the "E" character, and the opening direction of the "E" character cannot be seen at any other position, the non-central gaze deviation angle of the left eye is determined to be 5 °, and the direction is determined to be the temporal side (relative position outside the eyeball) of the macula fovea line, and the abnormal retinal imaging point is located at the position of 5 ° viewing angle on the nasal side of the macula fovea on the retina.

Meanwhile, the eye movement point calculation module monitors the left eye movement point of the tested person in real time, if the left eye movement point is separated from the position displayed by the first visual target, the position of the first visual target is moved in real time to be equal to the position of the left eye movement point, and the display position of the second visual target is moved to keep the relative position (the difference value of the relative visual angles) of the second visual target and the first visual target unchanged; or the test result is invalid during the period that the left eye movement point is away from the first sighting target position, and the test is conducted again.

Example III

Some subjects, such as young children, cannot accurately express whether or not the visual target is clearly seen. Thus, visual evoked potentials can be used to objectively record the degree of visual acuity at different locations of the subject's retina.

For example, one subject is known to have his left eye as a non-central gaze, and is of the type "stable non-central gaze".

A visual detection device comprises a display module, an image shooting and processing module, an eye movement point calculation module, a visual evoked potential calculation module and a non-central gazing deviation angle calculation module. The system also comprises an electronic computer, wherein an image processing algorithm of the image shooting and processing module, an eye movement point calculating module and a non-central gazing deviation angle calculating module are all programs running on the electronic computer. In addition, the apparatus comprises a head fixation device on which the chin of the subject is placed, the distance between the head fixation device and the display module being fixed and known.

The device composition and working principle of the image shooting and processing module and the eye movement point calculating module are the same as those of the embodiment.

The visual evoked potential calculation module is used for stimulating eyes in a flashing or pattern, and recording visual evoked potentials (visual evoked potential, VEP) in occipital visual cortex areas through skin electrodes arranged at corresponding positions of scalp.

The specific working mode of the non-central gazing deviation angle detection module is as follows:

Firstly, an image shooting and processing module and an eye movement point calculating module perform monocular calibration on a left eye, and calculate the eye movement point of the left eye in real time according to the shot image. Then, the display module displays the optotype, and the person to be examined needs to look at the optotype, in this embodiment, the optotype is a "+" character, and the line connecting the pupil center of the B-eye and the optotype is the first line of sight. A periodic scintillation spot is displayed at a variable position within a1 deg. radius to 10 deg. radius view around the optotype. The positions of the scintillation light spots are displayed on grid points at intervals of 1 DEG in the longitudinal direction and the transverse direction in the range of 1 DEG radius to 10 DEG radius angles around the optotype, each position is sequentially displayed from left to right and from top to bottom, and the scintillation light spots repeatedly flash for a plurality of times, and the VEP waveforms are overlapped to improve the signal to noise ratio. The visual evoked potential calculating module records the visual evoked potential and corresponds to the position displayed by the flickering light spot.

In this way, after the glistening spot appears at all positions, the macula fovea area is the area most sensitive to vision, and although the macula fovea vision of a subject may be inhibited to a certain extent due to strabismus and the like, the macula fovea area is still more likely to be the area most sensitive to the visual evoked potential induced by the glistening spot around the abnormal retinal imaging point corresponding to the abnormal vision line. By displaying the scintillation light spot in the range of the radius view angle from 1 DEG to 10 DEG around the visual target, if the area with the relatively obvious highest visual evoked potential amplitude exists, the connection line between the position of the scintillation light spot and the pupil center at the moment can be judged to be the macula fovea line of sight, the scintillation light spot is imaged at the macula fovea position at the moment, the connection line between the left eye pupil center and the display position of the scintillation light spot at the moment is the line of sight II, and the non-central gaze deviation angle is the included angle between the line of sight I and the line of sight II.

Meanwhile, the eye movement point calculation module monitors the left eye movement point of the tested person in real time, if the left eye movement point leaves the position displayed by the visual target, the position of the visual target is moved in real time to be equal to the position of the left eye movement point, and the display position of the flickering light spot is moved to keep the display position of the flickering light spot and the relative position (the difference value of the relative visual angles) of the visual target unchanged; or the test result is invalid when the left eye movement point is away from the sighting target position, and the test is conducted again.

Example IV

The embodiment discloses a visual training device, which can perform visual training on stable non-central fixation.

For example, a patient with a non-central gaze is known to have a non-central gaze with the left eye, a stable non-central gaze and a known non-central gaze deviation angle, the relative positions of the abnormal retinal imaging point and the fovea of the left eye being fixed.

A visual training device comprises a display module, an image shooting and processing module, an eye movement point calculation module, a macula fovea sight intersection point calculation module and a training module.

In this embodiment, the display module is a display, and the displayed content is visible only to the left eye and not to the right eye. The method can be realized by shielding the right eye with an eyeshade or by a polarized display, a naked eye 3D display and the like in the first embodiment.

The device composition and the working principle of the image shooting and processing module are the same as those of the embodiment.

The device composition and the working principle of the eye movement point calculating module are the same as those of the embodiment. The left eye movement point coordinates are the intersection points of the left eye abnormal vision line and the display plane.

The device also comprises an electronic computer, and an image processing algorithm of the image shooting and processing module, an eye movement point calculating module, a macula fovea sight intersection point calculating module and a training module are all programs running on the computer. The relative position and distance of the patient's eyes from the display is also known. According to the relative position and distance between the left eye and the display and the coordinates of the eye movement point of the left eye, the abnormal sight of the left eye can be obtained; according to the abnormal left eye sight and the non-central left eye gaze deviation angle, the central concave left eye macular sight can be calculated, and the intersection point of the central concave left eye macular sight and the display plane, namely the intersection point of the central concave left eye macular sight, is calculated.

In this embodiment, as shown in fig. 7, it is known that the left-eye non-central gaze deviation angle is 3 °, and the left-eye abnormal line of sight is on the temporal side (the relative position of the outside of the eyeball) of the macular fovea line of sight. The distance between the pupil center of the left eye and the display plane of the display is known to be 60cm. When the left eye is looking ahead, the intersection position of the left eye abnormal sight line and the display plane is W, and the left eye abnormal sight line is rotated clockwise by 3 degrees (clockwise direction seen from top to bottom), so that the left eye macula lutea central concave sight line is obtained. As can be seen from fig. 7, the intersection point C of the left-eye macular fovea line of sight and the display plane is directly right of W, which is calculated as 60cm×tan3 deg. c.about.3.1 cm, so that the left-eye macular fovea line of sight intersection point C is directly right of the intersection point W of the left-eye abnormal line of sight and the display plane by 3.1 cm.

The training module is a program running on a computer. In vision training, a clear image is displayed at the macula fovea line intersection, and no image or a suppressed image is displayed at the position of the left eye movement point (the intersection of the left eye abnormal line of sight and the display plane). The image is suppressed by one or more of blurring, lowering display resolution, darkening brightness and lowering contrast.

The training module can be used for displaying clear images at the intersection point of the central concave vision line of the macula lutea of the left eye during vision training, and the positions of the images displayed are moved along with the movement of the intersection point of the central concave vision line of the macula lutea of the left eye; no image is displayed at other positions of the display plane. During vision training, the image display range is not more than a circular range with the intersection point of the central concave vision line of the left eye macula as the center and the radius less than or equal to 2 degrees of visual angle. For example, the image may be numbers, chinese characters, letters, small optotypes, small animations, flashing light spots, etc. In this example, the image is an Arabic number changing every 2 seconds on the display plane, the viewing angle is 1, the displayed position is the intersection of the foveal line of sight of the left eye macula and the display plane, the patient is asked to see the Arabic number in a single eye and report orally to the doctor what the number is seen. No image is displayed at other positions of the display plane. Through vision training, the left eye macular fovea position of the patient can be always stimulated by the image, and the left eye abnormal retina imaging point position can not be stimulated by the image, so that the patient is helped to gradually recover normal macular fovea fixation.

The training module can also use a training mode that the display module displays clear images near the intersection point of the central concave vision line of the left eye macula, displays depressed images in the region with the farther intersection point of the central concave vision line of the left eye macula, and the displayed positions of the images do not move along with the movement of the intersection point of the central concave vision line of the left eye macula during vision training. When the image is displayed on the display module, the range of displaying the clear image is not more than the circular range with the central concave sight line intersection point of the yellow spot of the left eye as the center of a circle and the radius is less than or equal to 2 degrees of visual angle. For example, in this embodiment, an image is displayed on the display, the image is a complete text, the position of the image displayed does not move along with the movement of the fovea line of sight of the macula of the left eye, but the image is clearly displayed in a range that the intersection point C of the fovea line of the macula of the left eye is the center of a circle, the area with a viewing angle of 1 ° radius is the blurred image, and other areas are blurred images. Thus, when a patient reads the text with a left eye, the patient can only see the text image near the intersection point of the central concave vision of the macula of the left eye, and the imaging point of the abnormal retina of the left eye corresponds to the blurred text image. Through vision training, the device is helpful for patients to strengthen the ability of the macular fovea fixation and gradually recover the normal macular fovea fixation.

Example five

The equipment composition and the working principle of the display module, the image shooting and processing module, the eye movement point calculating module and the macula lutea fovea sight intersection point calculating module are the same as those of the fourth embodiment. Wherein the content displayed by the display module is visible only to the left eye and not to the right eye. In addition, the apparatus comprises a head fixation device on which the chin of the subject is placed, the distance between the head fixation device and the display module being fixed and known. The training module in this embodiment is a program running on a computer. During vision training, firstly, an image P ₁ is displayed at an intersection point W of the abnormal sight line of the left eye and a display plane, an image P ₂ is displayed at an intersection point C of the fovea sight line of the left eye and the display plane, and the displayed range of the image P ₁ and the displayed range of the image P ₂ are not more than the circular range of the visual angle with the radius less than or equal to 2 degrees. Under the condition of keeping the left eye movement point position unchanged (namely, the positions of the eyes are unchanged, W and C) the image P ₁ is gradually depressed, and vision training is carried out. The image is suppressed by one or more of blurring, lowering display resolution, darkening brightness, and lowering contrast.

For example, a blinking blue light spot is displayed at the position of the intersection point W of the abnormal line of sight of the left eye and the display plane of the patient right in front of the left eye, a blinking red light spot is displayed at the position of the intersection point C of the fovea line of sight of the left eye and the display plane, the red light spot and the blue light spot are the same in size, and the blinking frequency is the same. Let the patient look at the blue spot.

First, the brightness of the blue light spot and the brightness of the red light spot are the same, and are both L ₀. When a patient looks at the blue spot with an abnormal line of sight to the left eye, the blue spot is imaged on an abnormal retinal imaging point while the red spot is imaged at the fovea of the macula. Because the left eye of the patient is a non-central gaze, the foveal vision is inhibited, and the foveal vision sensitivity may be lower than that of the abnormal retinal imaging point, so the patient may subjectively feel that the red light spot is weaker than the blue light spot.

Then, the brightness of the blue spot is gradually reduced, and the brightness of the red spot remains unchanged. When the brightness of the blue light spot is reduced to a certain degree, the patient can subjectively feel that the brightness of the red light spot is the same as the brightness of the blue light spot, and the brightness of the blue light spot is recorded as L ₁.

Next, the brightness of the blue spot is gradually reduced further, and the brightness of the red spot remains unchanged. The patient perceives the blue spot to be significantly weaker than the red spot, and if the blue spot is further reduced below the threshold L ₂, the patient may inadvertently look at the red spot with an abnormal line of sight because the blue spot is not visible. The brightness of the blue light spot is kept equal to L ₂ or slightly larger than L ₂ and smaller than L ₁, so that the fovea position of the macula of a patient can be stimulated strongly all the time, and the abnormal retina imaging point corresponding to the abnormal vision is stimulated as weak as possible. Through such vision training, the ability of the patient to strengthen the foveal gaze is facilitated, and the normal foveal gaze is gradually restored.

As the foveal gaze ability gradually increases as vision training continues for a period of time, the ratio of L ₂/L₀ gradually decreases, and even when the foveal gaze ability returns to near normal vision levels, the brightness of the blue spot may remain gazing at the red spot with the foveal gaze even if the brightness of the patient drops to 0.

Example six

The visual training device disclosed by the embodiment can perform visual training on non-central fixation, and is not only suitable for stable non-central fixation, but also suitable for wandering non-central fixation.

For example, a non-central fixation patient, whose left eye is known to be a wandering non-central fixation, has abnormal retinal imaging points and macular fovea in the left eye at a non-fixed relative position. The right eye is the central gaze eye and the Kappa angle of the right eye is known. The measurement of the Kappa angle of the right eye may be the measurement of the first embodiment, or may be another measurement of Kappa angle.

A visual training device comprises a display module, an image shooting and processing module, a macula fovea line of sight intersection point calculating module and a training module. The system also comprises an electronic computer, wherein the algorithm of the image shooting and processing module, the macula fovea vision calculation module and the training module are all programs running on the electronic computer. In addition, the device also comprises a head fixing device, the chin of the subject is placed on the head fixing device, the heights of the left eye and the right eye are the same, the distances between the left eye and the right eye and the display are the same, and the distances between the head fixing device and the display module are fixed and known.

In this embodiment, the display module is a display.

The image shooting and processing module comprises 2 near infrared cameras and 2 near infrared light sources, and can continuously shoot images of the left eye; the system comprises an image processing function, and can perform image processing calculation on the shot image of the region to obtain a three-dimensional coordinate of the center of the pupil of the left eye and a three-dimensional coordinate of the center of each cornea reflecting point of the left eye, and the relative positions of the image shooting and processing module and the display module are known.

The macula fovea line intersection point calculating module can calculate the intersection point of the macula fovea line of the left eye and the display plane in real time. The principle is that the left eye pupil midline can be calculated in real time by using the measurement mode in the first embodiment. According to the principle of physiological symmetry of the left eye and the right eye, the included angle beta between the central concave view line of the macula of the left eye and the central line of the pupil of the left eye is equal to the Kappa angle alpha of the right eye, and the included angle direction is in mirror symmetry with the median sagittal plane of the human body. Therefore, the central concave vision of the left eye macula can be calculated in real time according to the pupil midline of the left eye and the included angle beta. And because the relative positions of the image shooting and processing module and the display module are known, the device can calculate the intersection point of the central fovea line of the left eye macular and the display plane of the display module in real time, and the position of the intersection point is set as C.

The training module displays clear images near the central concave vision intersection point of the left eye macula lutea during vision training, and does not display images or displays depressed images in other areas. Through the visual training, the macula fovea can always obtain the visual stimulus of clear images, and the patient is helped to gradually restore normal macula fovea fixation.

For example, in vision training, a clear image is displayed at the intersection of the central concave vision lines of the macula lutea of the left eye, and the image is displayed in a range not exceeding a circular range with the intersection of the central concave vision lines of the macula lutea of the left eye as the center and with a radius of 2 degrees or less. When the macula lutea fovea line intersection point moves, the position of the image display moves along with the macula lutea fovea line intersection point; no image is displayed at other positions of the display plane. The image may be numbers, chinese characters, letters, small optotypes, small animations, flashing light spots, etc. In this embodiment, the image is a Chinese character changing every 2 seconds on the display plane, the viewing angle is 1 °, the displayed position is the intersection of the left eye macular fovea line of sight and the display plane, the left eye of the patient is required to view the Chinese character and orally report to the doctor what the Chinese character is seen. No image is displayed at other positions of the display plane.

For example, during vision training, the display module displays clear images near the intersection point of the central concave vision line of the left eye macula, and the range of displaying the clear images does not exceed the circular range with the intersection point of the central concave vision line of the left eye macula as the center, and the radius is less than or equal to 2 degrees. The area outside this range displays a suppressed image, and the image may be suppressed by one or more of blurring, lowering of display resolution, darkening of brightness, lowering of contrast, and the like. The position of the image display does not move with the movement of the central concave line of sight intersection of the macula of the left eye. In this embodiment, the image displayed on the display is a complete text, the position of the image displayed does not move along with the movement of the eye sight, but the clear display range of the image is a region with the intersection point C of the central concave sight of the macula lutea of the left eye as the center of a circle and the view angle of radius 1 degree, and other regions are blurred images. Thus, when a patient reads the text with a left eye, the patient can only see the text image near the intersection point of the central concave vision of the macula of the left eye, and the imaging point of the abnormal retina of the left eye corresponds to the blurred text image.

Example seven

The embodiment discloses a visual training device, which performs visual training on non-central fixation by using the simultaneous vision function, or the fusion vision function and the stereoscopic vision function of binocular vision.

A patient, the right eye is a central gazing eye, the left eye is a non-central gazing eye, the left eye is a stable non-central gazing, the non-central gazing deviation angle is known, and the relative positions of abnormal retina imaging points and macula fovea of the left eye are fixed.

A visual training device comprises a display module, an image shooting and processing module, an eye movement point calculation module, a macula fovea sight intersection point calculation module and a training module. The system also comprises an electronic computer, wherein the algorithm of the image shooting and processing module, the macula fovea vision calculation module and the training module are all programs running on the electronic computer. In addition, the apparatus comprises a head fixation device on which the chin of the subject is placed, the distance between the head fixation device and the display module being fixed and known.

The display module in this embodiment is a polarized display, and the patient wears polarized glasses, and the polarized display can display an image visible only by a left eye and an image visible only by a right eye. The polarized glasses worn by the patient can transmit 850nm near infrared light.

The image capturing and processing module in this embodiment includes 1 near infrared camera and 2 LED near infrared light sources with light emission wavelength of 850nm, and its components and working principle are similar to those of the eye movement point calculating module in the second embodiment, but the eye movement point calculating module in this embodiment can capture images of left eye and right eye. The eye movement point calculation module in the embodiment firstly carries out monocular calibration on the right eye and the left eye respectively; when the right eye is in monocular calibration, only the right eye can see the calibration visual target displayed by the display module, a calibration function of the right eye is obtained through the monocular calibration of the right eye, after the calibration of the right eye is finished, the coordinates of the right eye moving point are calculated according to the right eye image and the calibration function of the right eye, and the coordinates of the right eye moving point are the intersection point of the concave central line of sight of the macula of the right eye and the display plane; when the left eye is in monocular calibration, only the left eye can see the calibration optotype displayed by the display module, the calibration function of the left eye is obtained through the monocular calibration of the left eye, after the calibration of the left eye is finished, the coordinates of the left eye moving point are calculated according to the left eye image and the calibration function of the left eye, and the coordinates of the left eye moving point are the intersection point of the abnormal line of sight of the left eye and the display plane. The method of monocular calibration and the method of calculating the eye movement point are similar to those in the second embodiment. In another embodiment, the image capturing and processing module may further be a device including two near infrared cameras and two near infrared light sources, so that the left eye and the right eye can obtain respective calibration functions through single-point calibration of a single eye, and then respective eye movement point coordinates of the left eye and the right eye are calculated through the eye movement point calculation module.

The working principle of the macula fovea line intersection point calculating module is as follows: because the relative position and distance between the left eye and the display are known, the left eye abnormal sight line is a straight line passing through the center position of the left eye pupil and the left eye movement point, and the left eye macula fovea sight line can be calculated according to the left eye abnormal sight line and the non-center gaze deviation angle; the intersection point of the left eye macula fovea line is the intersection point of the left eye macula fovea line and the display plane.

The training module is used for displaying an image P _A visible only to the right eye during vision training; let the trainer look at the image P _A, and then display an image P _B visible only to the left eye at the intersection of the left eye macular fovea line of sight and the display module; then image P _A and image P _B remain displayed simultaneously for visual training. In this embodiment, the range displayed by the image P _A and the image P _B does not exceed the circular range of viewing angles with a radius of 2 °.

In vision training, images P _A and P _B may be complementary images, and the patient may attempt to complement the left and right eye images into a complete image in the brain, which may simultaneously train the patient's simultaneous vision functions. For example, image P _A is a birdcage, only visible to the right eye; image P _B is a bird, which is visible only to the left eye. Then the doctor asks the patient whether the bird and the birdcage can be seen at the same time, and if so, the doctor indicates that the patient has the simultaneous vision; if the patient can only see the bird or can only see the birdcage, it is indicated that the patient does not have simultaneous vision and further training is required.

In vision training, the images P _A and P _B may be identical images of the same shape and size, and the patient may attempt to fuse the left eye-seen image and the right eye-seen image into a single image in the brain, so that the fusion vision function of the patient may be trained simultaneously. For example, image P _A is a bird, which is visible only to the right eye; image P _B is an identical bird, which is visible only to the left eye. Then the doctor asks the patient to see a plurality of birds, if one bird is seen, the doctor indicates that the patient has a fusion view; if two birds are seen, this indicates that the patient does not yet have fusion vision and further training is required.

In vision training, the images P _A and P _B may also be stereoscopic images with binocular disparity, and the patient may try to generate stereoscopic vision in the brain from the images seen by the left eye and the images seen by the right eye, so that the stereoscopic vision function of the patient may be trained simultaneously. For example, the image P _A and the image P _B may be combined into a stereoscopic image of a sphere that can be scrolled back and forth in a loop. Then the doctor asks the patient whether to see a ball to roll back and forth, whether the current distance is far or near, if the patient can correctly identify the ball and judge the distance, the three-dimensional vision is provided; if the patient cannot correctly identify the ball and judge the distance, the patient is not provided with a stereoscopic vision, and further training is needed.

When the left-eye macular fovea line intersection point changes, the position of the image P _B can be moved along with the change, and the image P _B is always positioned at the position of the left-eye macular fovea line intersection point, so that the image P _B is imaged at the left-eye macular fovea position.

Example eight

A non-central fixation patient is known to have a non-central fixation for the left eye and a central fixation for the right eye, and the Kappa angle for the right eye is known. The measurement of the Kappa angle of the right eye may be the measurement of the first embodiment, or may be another measurement of Kappa angle.

A visual training device comprises an image shooting and processing module, a macula fovea sight calculating module and a liquid crystal shielding module.

The image shooting and processing module comprises 2 near infrared cameras and 2 near infrared light sources, and can continuously shoot images of the left eye; the system comprises an image processing function, and can perform image processing calculation on the shot image of the region to obtain the three-dimensional coordinates of the center of the pupil of the left eye and the three-dimensional coordinates of the center of the reflection point of each cornea of the left eye.

The macula fovea line of sight calculation module can calculate the intersection point of the macula fovea line of sight and the display plane of the left eye in real time. The principle is that the left eye pupil midline can be calculated in real time by using the measurement mode in the first embodiment. According to the principle of physiological symmetry of the left eye and the right eye, the included angle beta between the central concave view line of the macula of the left eye and the central line of the pupil of the left eye is equal to the Kappa angle alpha of the right eye, and the included angle direction is in mirror symmetry with the median sagittal plane of the human body. Therefore, the central concave vision of the left eye macula can be calculated in real time according to the central line of the left eye pupil and the included angle beta.

The liquid crystal shielding module is a liquid crystal lens positioned in the left eye visual field range, the liquid crystal shielding module can control the liquid crystal lens to be transparent in the range near the intersection point of the macula fovea line of sight of the left eye and the liquid crystal lens, other areas are opaque, vision training is carried out, the position of the transparent area can be changed in real time according to the change of the macula fovea line of sight of the left eye of a patient, and the transparent area is always positioned at the intersection point of the macula fovea line of sight of the left eye and the liquid crystal lens. The relative positions of the liquid crystal shielding module and the image shooting and processing module are fixed and known. The transparent or opaque mode of any area of the liquid crystal lens can be controlled by a program running on an electronic computer or by a miniaturized embedded system such as an FPGA. The transparent range of the liquid crystal shielding module is not more than the circular range with the central concave view line intersection point of the macula as the center of a circle and the radius less than or equal to 2 degrees of view angle. In this embodiment, a circular range having a radius equal to the viewing angle of 1 ° is set. In this way, the left eye of the patient can see the visual field area, only the macular fovea area of the left eye of the patient can be imaged, continuous imaging stimulation is carried out on the macular fovea area of the left eye of the patient, and at the same time, the abnormal retinal imaging point corresponding to the abnormal sight line of the left eye cannot be stimulated by an external image, so that the patient can be helped to recover the macular fovea fixation.

In performing visual training, the content of the visual training may be images, video, animation, etc. on the display. The device may also be integrated into a wearable headset, such as a pair of headphones, VR device, AR device, or the like. For example, when the present device is integrated into a head-mounted eyeglass, a patient can wear such eyeglass for a long period of time, and perform visual training in daily life or learning.

Claims

1. A visual inspection apparatus having one of both eyes as a central gazing eye, referred to as an a eye, and the other eye as a non-central gazing eye, referred to as a B eye, comprising:

A display module;

2. The visual inspection apparatus according to claim 1, further comprising a judging module for calculating an angle between a central concave line of sight of a macula of the B-eye and an abnormal line of sight of the B-eye when the B-eye gazes at the visual target; and when the included angle between the central concave view line of the macula of the eye B and the abnormal view line of the eye B is a stable value within a period of time, the judging module judges that the eye B is stable non-central fixation.

3. The visual inspection apparatus according to claim 1, further comprising a judging module for calculating an angle between a central concave line of sight of a macula of the B-eye and an abnormal line of sight of the B-eye when the B-eye gazes at the visual target; and when the included angle between the central concave view line of the macula of the eye B and the abnormal view line of the eye B is an unstable value within a period of time, the judging module judges that the eye B is the wandering non-central gazing.

4. A vision training device, provided that one of the eyes is a non-central gaze eye, called B eye, which is known as a stable non-central gaze and that obtains a non-central gaze deviation angle by the vision detection device of claim 1, characterized by comprising:

5. The vision training apparatus of claim 4, wherein in the training module, the training module controls the display module to display a clear image near the B-eye macular fovea line of sight intersection, and when the B-eye macular fovea line of sight intersection moves, the position of the image display moves; and displaying no image at other positions of the display plane of the display module.

6. The vision training device according to claim 5, wherein in the training module, the range of image display does not exceed the circular range with the central concave line of sight intersection of the macula lutea of the B eye as the center and the radius is equal to or less than 2 ° visual angle during vision training.

7. The vision training apparatus according to claim 4, wherein the training module, during the vision training, the display module displays a clear image near the B-eye macula fovea line intersection, displays a suppressed image in a region farther from the B-eye macula fovea line intersection, and the position of the image display does not move with the movement of the B-eye macula fovea line intersection.

8. The vision training device of claim 5, wherein in the training module, when the training module controls the display module to display the image, a range of displaying the clear image does not exceed a circular range with a central concave line of sight intersection of a macula of a B eye as a center, and a radius is less than or equal to 2 ° of viewing angle.

9. A vision training device, provided that one of the eyes is a non-central gaze eye, called B eye, which is known as a stable non-central gaze and that obtains a non-central gaze deviation angle by the vision detection device of claim 1, characterized by comprising:

10. The vision training device of claim 9, wherein in the training module, the images P ₁ and P ₂ are displayed in a range that does not exceed a circular range of viewing angles having a radius of +.2 °.

11. A vision training device, one of the eyes being a central gazing eye, referred to as an a eye, and the other eye being a non-central gazing eye, referred to as a B eye, obtained by the vision inspection device of claim 1, comprising:

12. The vision training device of claim 11, wherein in the training module, during vision training, an image is displayed at the B-eye macula fovea line intersection, and the position of the image display moves as the B-eye macula fovea line intersection moves; no image is displayed at other positions of the display plane.

13. The vision training device of claim 12, wherein in the training module, the range of image display does not exceed the circular range with the central concave line of sight intersection of the macula lutea of the B eye as the center and the radius is equal to or less than 2 ° visual angle during vision training.

14. The vision training apparatus according to claim 11, wherein in the training module, the display module displays a clear image near the B-eye macula fovea line intersection, displays a suppressed image in a region farther from the B-eye macula fovea line intersection, and the position of the image display does not move with the movement of the B-eye macula fovea line intersection during the vision training.

15. The vision training device of claim 14, wherein the training module displays the image on the display module in a range not exceeding a circular range with a radius of 2 ° or less with respect to the point of intersection of the foveal lines of the macula of the B eye as the center.

16. A vision training device having one of both eyes as a central gazing eye, called an a eye, and the other eye as a non-central gazing eye, called a B eye, which is known as a stable non-central gazing and which obtains a non-central gazing deviation angle by the vision inspection device according to claim 1, comprising:

17. The vision training device of claim 16, wherein the training module is configured to simultaneously view the images P _A and P _B to form a complete image during vision training.

18. The vision training device of claim 16, wherein in the training module, the image P _A and the image P _B are the same shape and size images during vision training.

19. The vision training device of claim 16, wherein in the training module, the images P _A and P _B are stereoscopic images with binocular disparity during vision training.

20. The visual training device of any one of claims 16 to 19, wherein the training module wherein the images P _A and P _B display a range not exceeding a circular range of viewing angles of radius +.2 °.

21. The vision training apparatus of any one of claims 16 to 19, wherein the position of the image P _B moves with the change in the B-eye macula fovea line intersection, always at the position of the B-eye macula fovea line intersection.

22. A vision training device, one of the eyes being a central gazing eye, referred to as an a eye, and the other eye being a non-central gazing eye, referred to as a B eye, obtained by the vision inspection device of claim 1, comprising:

23. The vision training device of claim 22, wherein the liquid crystal shielding module is transparent within a range not exceeding a circular range with a radius of 2 ° or less with respect to the center concave line of sight intersection of the macula lutea of the B eye as a center.

24. The vision training device of claim 22, wherein the vision training device is integrated into a headset, the headset being a pair of glasses, a VR device, or an AR device.