A strabismus training device

Abstract

The present invention provides a strabismus training device, which is characterized by comprising a display module; an image capturing and processing module; a calibration module; an eye movement point calculation module; and a strabismus training prism diopter range calculation module. The beneficial effects of the present invention are as follows: on the basis of maintaining binocular fusion vision, by performing visual training on strabismus patients, the strabismus degree is gradually reduced, achieving the effect of treating strabismus without surgery.

Description

[0001] Divisional Application Statement

[0002] This application is a divisional application of the Chinese invention patent application with the invention name "Strabismus Training Device", application number 202110022646.X, filed on January 8, 2021. Technical Field

[0003] The present invention relates to the field of ophthalmic medical devices, and particularly to a strabismus training device. Background Art

[0004] Strabismus is a common disease in ophthalmology. The current treatment methods for strabismus are mainly surgical treatment and visual training. Generally speaking, strabismus patients can first try visual training. If they can recover to normal through visual training, it can avoid the physical and mental pain brought to the patients by surgery and also avoid the possible side effects of surgery.

[0005] Traditional visual training methods generally involve wearing prisms for binocular vision training, but there are currently difficulties in selecting the prism diopter during visual training. Because if the visual training prism diopter is equal to the strabismus prism diopter, although the patient feels relatively comfortable subjectively, the eye muscles remain in a relatively large strabismus state and it is not easy to change the strabismus degree through training, resulting in poor training effects; if the visual training prism diopter is much smaller than the strabismus prism diopter and close to the limit of binocular vision convergence and divergence, the patient will feel very uncomfortable and is prone to visual fatigue, which has an adverse impact on the training effect; even if the visual training prism diopter exceeds the limit of binocular vision convergence and divergence and destroys the fusion state, it will cause the patient to have diplopia or confusion of vision, and thus effective visual training effects cannot be achieved. Summary of the Invention

[0006] The purpose of the present invention is to provide a device for visual training of strabismus patients while maintaining binocular fusion vision.

[0007] To achieve the above purpose, the technical solution of the present invention is to provide a strabismus training device, which is characterized by comprising:

[0008] A display module;

[0009] An image capturing and processing module, including at least one camera, which can continuously capture images of the left eye and the right eye;

[0010] A calibration module, used to perform monocular calibration on the left eye and the right eye respectively; when performing left-eye monocular calibration, only the left eye can see the calibration target displayed on the display module; when performing right-eye monocular calibration, only the right eye can see the calibration target displayed on the display module; the left-eye calibration function is obtained through left-eye monocular calibration, and the right-eye calibration function is obtained through right-eye monocular calibration;

[0011] Eye movement point calculation module, after the calibration of the left eye and the right eye is completed, calculate the coordinates of the left eye movement point according to the left eye image and the left eye calibration function, and calculate the coordinates of the right eye movement point according to the right eye image and the right eye calibration function;

[0012] Strabismus training prism diopter range calculation module, assume that one of the two eyes is a strabismic eye and the other is a non-strabismic eye, the strabismus direction of the strabismic eye is known, and the known strabismus prism diopter is L0; calculate the strabismus training prism diopter range through the following steps:

[0013] (a) Display a visual target visible to both eyes directly in front of the subject and let the subject fixate on the visual target; at this time, the prism diopter of the prism worn by the strabismic eye is L0;

[0014] (b) Gradually reduce the prism diopter of the strabismic eye prism. Let the prism diopter of each newly replaced prism be L, define ΔL=(L0 - L), define F as the distance between the eye movement point of the strabismic eye and the eye movement point of the non-strabismic eye, and record the value of F changing with ΔL;

[0015] (c) Set a threshold value F0, and find the maximum ΔL value ΔL1 corresponding to F≤F0; and the value of the prism diopter L corresponding to this time can be obtained, denoted as L min ;

[0016] (d) The strabismus training prism diopter range is: assume the strabismus training prism diopter is L x , L x 's value range is L min <L x <L0; during the strabismus training process, let the strabismic eye wear a prism with a prism diopter of L x for strabismus training.

[0017] Preferably, the threshold value F0 is the distance corresponding to an angle of view between 2° and 5° of view on the display plane of the display module.

[0018] Preferably, establish a rectangular coordinate system, the two coordinate axes of the rectangular coordinate system respectively correspond to the F and the ΔL, take the value of the F and the corresponding value of the ΔL as the coordinate points in the rectangular coordinate system, connect each coordinate point to form a line graph, then the threshold value F0 is the value of the F corresponding to the change of the line segment slope from less than 1 to greater than or equal to 1 in the line graph.

[0019] Preferably, set L x to any fixed value between (L min + 0.1×ΔL1) and (L0 - 0.1×ΔL1) as the strabismus training prism diopter.

[0020] Preferably, set L x = (L0 + L min ) / 2 as the strabismus training prism diopter.

[0021] Preferably, if the squinting eye is also an amblyopic eye, a suppression module is further included, and the suppression module suppresses the non-squinting eye to keep the two eyes in the visual acuity balance range.

[0022] Preferably, a strabismus training module is further included. The strabismus training module is controlled by a program, and the training content is static images, or dynamic videos and animations displayed on a display device; the prism diopter of the prism worn by the squinting eye is L x 。

[0023] Preferably, a strabismus training module is further included. The strabismus training module is controlled by a program, and the training content is an interactive game displayed on a display device. The interactive content in the game can be controlled by the eye movement points for real-time interaction; the prism diopter of the prism worn by the squinting eye is L x 。

[0024] Preferably, a monitor display is further included, and the training content of the strabismus training module, the eye movement points of the squinting eye, and / or the eye movement points of the non-squinting eye can be displayed on the monitor display in real time.

[0025] Preferably, a strabismus training module is further included. The strabismus training method is that the squinting eye wears a prism with a prism diopter of L x in daily life, and the strabismus training is carried out by watching real objects.

[0026] Preferably, after a period of training, the strabismus prism diopter of the patient is retested, and the value of ΔL1 is re-measured according to the new strabismus prism diopter; then the new value of L min is obtained, and the new value of L min is used to calculate the new value of L x as the strabismus training prism diopter; and the new value of L x is used for the strabismus training module to carry out strabismus training; this process can be cycled multiple times.

[0027] The beneficial effect of the present invention is that on the basis of maintaining binocular fusion vision, by performing visual training on strabismus patients, the strabismus degree is gradually reduced, achieving the effect of treating strabismus without surgery. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic diagram of the components of the strabismus training device in Embodiment 1;

[0029] Figures 2(a) to 2(c) is a schematic diagram of the positional relationship among the target A, the left eye movement point, the target B, and the right eye movement point as the target B moves in Embodiment 1;

[0030] Figure 3 is a schematic diagram of the change of the D value with the P value in Embodiment 1;

[0031] Figure 4 It is a schematic diagram showing the change of the F value with the ΔL value in the fourth embodiment. Specific implementation manners

[0032] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application.

[0033] Embodiment 1

[0034] As Figure 1 shown, a strabismus training device disclosed in this embodiment includes a display module, an image capturing and processing module 105, a calibration module, an eye movement point analysis module, and a strabismus training image displacement range calculation module. It also includes an electronic computer, and the image processing algorithm of the image capturing and processing module 105, the calibration module, the eye movement point calculation module, and the eye movement point analysis module are all programs running on this electronic computer. In order to further improve the clarity of the images captured by the image capturing and processing module 105 and reduce the eye movement test error caused by head movement, a head fixing bracket 104 is used for head fixing in this embodiment.

[0035] In this embodiment, the display module is a polarization display 101 that can emit two types of polarized light, and two polarizing films, a left polarizing film 102 and a right polarizing film 103, are used in cooperation. The left polarizing film 102 is located between the left eye and the polarization display 101, and the right polarizing film 103 is located between the right eye and the polarization display 101. The polarization display 101 can emit left-handed circularly polarized light or right-handed circularly polarized light. When the display device displays an image composed only of left-handed circularly polarized light, the left eye can see the image through the left polarizing film 102, and the right eye cannot see the image through the right polarizing film 103; when the polarization display 101 displays an image composed only of right-handed circularly polarized light, the right eye can see the image through the right polarizing film 103, and the left eye cannot see the image through the left polarizing film 102. The two polarizing films can be fixed on the head fixing bracket 104, or can be designed to be worn on the head like glasses. In this embodiment, they are fixed on the head fixing bracket 104.

[0036] In this embodiment, the image capturing and processing module 105 includes one near-infrared camera and two LED near-infrared light sources with a light-emitting wavelength of 850 nm. The two near-infrared light sources are located on both sides of the near-infrared camera and are point light sources. The near-infrared camera and the near-infrared light sources are placed inside the housing of the image capturing and processing module 105. The image capturing and processing module 105 is located below the polarization display 101. Since the left polarizer 102 and the right polarizer 103 in this embodiment can both transmit near-infrared light, the near-infrared camera in the image capturing and processing module 105 can capture images of the left and right eyes of a person. The near-infrared light sources provide illumination for the near-infrared camera to capture images, and corneal reflection points are generated through reflection on the outer surface of the cornea, which can be captured by the near-infrared camera and used as reference points for eye movement point calculation. The image capturing and processing module 105 can perform image processing calculations on the captured eye images to obtain the center coordinates of the left eye pupil, the center coordinates of each corneal reflection point of the left eye, the center coordinates of the right eye pupil, and the center coordinates of each corneal reflection point of the right eye. The image processing algorithm used in this embodiment is as follows: Since the corneal reflection points captured by the near-infrared camera have high brightness and the gray level can reach 255, and two corneal reflection points appear in pairs and are close in distance. According to this characteristic, the image areas where the left and right eyes are located can be found from the entire image captured by the infrared camera. A gray level threshold higher than the pupil gray level and lower than the gray levels of the surrounding iris and skin areas is set, and the areas below the gray level threshold are marked as possible pupil areas; then an area threshold is set to exclude the interference of smaller black objects such as eyelashes, so as to determine the accurate area where the pupil is located. The coordinates of the center of the left eye pupil are obtained according to the center of the left eye pupil area; the center coordinates of the left corneal reflection point are obtained according to the average coordinates of the center coordinates of the two corneal reflection points of the left eye. The left eye pupil corneal vector is obtained by subtracting the center coordinates of the left corneal reflection point from the center coordinates of the left eye pupil. Similarly, the center coordinates of the right eye pupil, the center coordinates of each corneal reflection point of the right eye, and the right eye pupil corneal vector can be obtained.

[0037] The function of the calibration module is to calculate the calibration mapping function of the left eye and the calibration mapping function of the right eye by respectively having the left and right eyes look at several calibration points on the display device.

[0038] The function of the eye movement point calculation module is to calculate the left eye movement point coordinates through the left eye pupil corneal vector and the left eye calibration mapping function after calibration; calculate the right eye movement point coordinates through the right eye pupil corneal vector and the right eye calibration mapping function.

[0039] The function of the strabismus training image displacement range calculation module is to calculate the relative displacement distance between the images seen by the strabismic eye and the non-strabismic eye.

[0040] Taking the strabismus training of a patient with right exotropia as an example, the specific process is as follows:

[0041] (1) The patient sits in front of this testing device, places the chin on the head fixation bracket 104, and directs the eyes towards the direction of the polarized display 101. The distance between the two eyes and the polarized display 101 is sixty centimeters. The near-infrared camera in the image capture and processing module 105 continuously captures images containing the binocular region, and calculates the pupil center and the corneal reflection point center in real time to obtain the left-eye pupil corneal vector and the right-eye pupil corneal vector.

[0042] (2) Calibration

[0043] The eye movement point is the intersection of the visual axis of the eyeball and the display plane. The left-eye movement point is the intersection of the left-eye visual axis and the display plane, and the right-eye movement point is the intersection of the right-eye visual axis and the display plane.

[0044] Taking the 9-point calibration method as an example, calibration targets are sequentially displayed at 9 different positions on the display. Substitute the pupil corneal vector and the calibration target coordinates when the left eye views the calibration target into the calibration mapping function equation set. After solving for the left-eye calibration mapping function coefficients, the left-eye calibration mapping function is obtained; substitute the pupil corneal vector and the calibration target coordinates when the right eye views the calibration target into the calibration mapping function equation set. After solving for the right-eye calibration mapping function coefficients, the right-eye calibration mapping function is obtained. The calibration module calibrates the left and right eyes separately, and the order of calibration of the left and right eyes is not limited. The calibration targets are points at 9 positions in the center, left, right, top, bottom, upper left, upper right, lower left, and lower right of the display, and the positions of these 9 points are known and determined.

[0045] During left-eye calibration, the polarized display 101 emits only left-handed circularly polarized light, so only the left eye can see the calibration points, and the right eye cannot see the calibration points. During right-eye calibration, the polarized display 101 emits only right-handed circularly polarized light, so only the right eye can see the calibration points, and the left eye cannot see the calibration points. The purpose of separately calibrating the left and right eyes is that for strabismus patients, since the binocular visual axes cannot simultaneously align with the target, if both eyes view the calibration points simultaneously, accurate calibration results cannot be obtained.

[0046] The following takes the 9-point calibration process of the left eye as an example.

[0047] 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 be the value of the horizontal direction of the pupil corneal vector, and y e be the value of the vertical direction of the pupil corneal vector.

[0048] Use the following mapping function ①:

[0049]

[0050] The 12 values of a0, a1, a2, a3, a4, a5, b0, b1, b2, b3, b4, and b5 are unknown before calibration. The calibration in the first stage is the process of solving these 12 unknowns.

[0051] Because 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 visual targets on the display plane are known; through the image capture and processing module 105, it can be calculated that the pupil-cornea vectors when looking at these 9 calibration visual targets are respectively (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 ). Substituting into the mapping function ①, the following system of equations ② composed of 18 equations can be obtained:

[0052]

[0053]

[0054] Because the number of equations is greater than the number of unknown variables at this time, the overdetermined system of equations needs to be solved by the least squares method to obtain the least squares solutions a0, a1, a2, a3, a4, a5, b0, b1, b2, b3, b4, b5.

[0055] Since the values of a0, a1, a2, a3, a4, a5, b0, b1, b2, b3, b4, b5 have all been solved as known values, substitute the horizontal direction value x of the pupil-cornea vector obtained by the image capture and processing module 105 e and the vertical direction value y of the pupil-cornea vector e into the mapping function ①, and the abscissa x of the eye movement point on the display plane can be calculated s and the ordinate y of the eye movement point on the display plane s . The pupil-cornea vector is obtained from the camera image, and its unit is pixel.

[0056] Using the above steps, after the left eye and the right eye are calibrated respectively, the calibration mapping function of the left eye and the calibration mapping function of the right eye are obtained. The eye movement point calculation module substitutes the left eye pupil-cornea vector obtained by the image capture and processing module 105 into the left eye calibration mapping function to calculate the eye movement point coordinates of the left eye; according to the right eye pupil-cornea vector captured and calculated by the image capture and processing module 105, substituting it into the right eye calibration mapping function can calculate the eye movement point coordinates of the right eye.

[0057] (3) Strabismus training image displacement range calculation module

[0058] In this embodiment, the subject is a patient with exotropia of the right eye. The left eye can see the image formed by the left-handed circularly polarized light through the left polarizer 102, which is called Image 1; the right eye can see the image formed by the right-handed circularly polarized light through the right polarizer 103, which is called Image 2. The left eye can only see Image 1 and cannot see Image 2; the right eye can only see Image 2 and cannot see Image 1. The strabismus training image displacement range is calculated through the following steps:

[0059] (a) Since the subject is a patient with exotropia of the right eye, if an image I visible only to the left eye, which is a visual target A, is displayed directly in front, when the left eye fixates on the visual target A, the visual axis of the right eye will deviate to the right by a certain angle, and there will also be a certain positional deviation between the corresponding eye movement point of the right eye and the position of the visual target A. Let the position where the eye movement point of the right eye is located at this time be S0, and the distance between S0 and the position where the visual target A is located be P0. In this embodiment, the eye movement point of the right eye is located 10 cm directly to the right of the visual target A, that is, P0 = 10 cm. Let S0 be the initial position, and an image II visible only to the right eye, which is a visual target B, is displayed at S0. The visual target B has the same size and shape as the visual target A. Fig. 2(a) is a schematic diagram of the positional relationship among the visual target A, the eye movement point of the left eye, the visual target B, and the eye movement point of the right eye. The eye movement point of the left eye is the intersection of the visual axis of the left eye and the display plane, and the eye movement point of the right eye is the intersection of the visual axis of the right eye and the display plane. If the strabismus patient has binocular fusion function and no abnormal retinal correspondence such as eccentric fixation, then at this time, the visual target A is imaged on the fovea centralis region of the left eye retina, and the visual target B is imaged on the fovea centralis region of the right eye retina. The brain fuses the images of both eyes into a single image, and subjectively, only one visual target will be seen.

[0060] (b) The visual target B is gradually moved in the direction towards the visual target A until it reaches the position where the two visual targets coincide at the farthest. During the movement, define P as the distance between the visual target B and its initial position S0, define E as the distance between the eye movement point of the right eye and the eye movement point of the left eye, define G as the distance between the visual target B and the visual target A, that is, G = P0 - P, define D = |E - G|, and record the value of D changing with P.

[0061] (c) Because there is a certain range for binocular fusion, if the imaging positions of the visual targets on the retinas of both eyes are within a certain range near the fovea centralis of the macula, the human brain can fuse the binocular images into a single image. However, if it exceeds this range, binocular fusion will be disrupted, and a person will see two images simultaneously. If the D value is too large and exceeds a certain threshold, it indicates a large deviation between the distance of the eye movement points of both eyes and the distance between the two visual targets. The imaging positions of the visual targets on the retinas of both eyes will necessarily differ greatly, and binocular fusion cannot be produced. Considering that the binocular fusion ranges of different people are different, and there may be certain errors in the accuracy and precision of eye movement point measurement, the threshold D0 is generally between 2° and 5° in terms of visual angle. In this embodiment, D0 is set to 3° visual angle. Since the distance between the eyes and the display is 60 cm, the distance corresponding to a 3° visual angle on the display is 60 cm × tan(3°) ≈ 3 cm. That is, on the display plane, D0 is 3 cm. Another way to set the D0 value is to connect the values of D changing with P with line segments. In the broken line graph of D changing with P, D0 is the D value corresponding to the point where the slope changes from less than 1 to greater than or equal to 1. Figure 2(b) is a schematic diagram of the positional relationship among visual target A, the left eye movement point, visual target B, and the right eye movement point during the movement of visual target B when binocular fusion can occur. The distance between the left eye movement point and the right eye movement point is slightly greater than the distance between visual target B and visual target A, but the difference does not exceed D0. Figure 2(c) is a schematic diagram of the positional relationship among visual target A, the left eye movement point, visual target B, and the right eye movement point during the movement of visual target B when binocular fusion cannot occur. From the graph of D value changing with P value, find the maximum P value P1 corresponding to D ≤ D0. Figure 3 It is a schematic diagram of the D value changing with the P value during the movement of visual target B.

[0062] (d) From the above steps, it can be calculated that the displacement range of the strabismus training image is: the displacement distance W of image two seen by the right eye relative to image one seen by the left eye x is between P0 and (P0 - P1), that is, (P0 - P1) < W x < P0, and the direction of the displacement of image two relative to image one is the direction of strabismus. Image two and image one have the same size and shape. Within this range, binocular fusion can be produced. And within this range, the visual angle difference between image two and image one is less than the angle of strabismus, which helps the patient gradually reduce the strabismus degree through visual training. W x If the value of W is selected too close to (P0 - P1), at the edge point of fusion rupture, the patient will easily feel visual fatigue; W x If the value of W is selected too close to P0, the effect of gradually reducing the strabismus degree through visual training may be slow. In actual use, the doctor can select a suitable W value for the patient between S1 and (S1 - P0) according to the patient's specific situation and usage feedback. x value. Generally, W can be set according to the training needs.x is a fixed value between (P0 - 0.9×P1) and (P0 - 0.1×P1), serving as the displacement distance of Image 2 relative to Image 1. In this embodiment, W is set x =(P0 - P0 / 2), which can not only ensure that the patient's vision is not easily fatigued, enabling the patient to persist in training for a longer time, but also has a certain distance from the area corresponding to the strabismus degree of the strabismic eye, allowing the patient to reduce the strabismus degree more quickly through training. In some cases, W can also be set x as a value that dynamically adjusts between (P0 - P1) and P0. For example, at the beginning stage of a visual training session, W is set x as a value close to (P0 - P1). During the visual training process, the visual fatigue degree of the patient is monitored in real time through data indicators such as the saccadic latency of eye movement. If the fatigue degree is relatively high, then W x is adjusted to a value closer to P0.

[0063] (IV) Strabismus training

[0064] After determining the strabismus training image displacement range and selecting the strabismus training image displacement distance W according to the foregoing steps x , strabismus training can be carried out.

[0065] The strabismus training module is a program running on a computer, and the training content can be in the following several ways:

[0066] The training content is to simultaneously display Image 1 visible only to the left eye (non-strabismic eye) and Image 2 visible only to the right eye (strabismic eye) on the display device. The contents of Image 1 and Image 2 are the same, being static images, or dynamic videos, animations; the displacement distance of Image 2 relative to Image 1 is W x , and the direction of the displacement of Image 2 relative to Image 1 is the strabismus direction.

[0067] The training content is to simultaneously display Image 1 visible only to the left eye (non-strabismic eye) and Image 2 visible only to the right eye (strabismic eye) on the display device. The contents of Image 1 and Image 2 are the same, and the content is an interactive game. The interactive content in the game can be controlled by the eye fixation point for real-time interaction; the displacement distance of Image 2 relative to Image 1 is W x , and the direction of the displacement of Image 2 relative to Image 1 is the strabismus direction. For example, the training content is a game of shooting balloons with the eyes: Colorful balloons appear randomly from below and float upward. The trainer controls the sight of a shooting gun with the eyes, and the position in the center of the sight is the eye fixation point position. By gazing at the balloon and lasting for one second, the balloon can be successfully burst. The game interface displays the number of balloons burst with the eyes in real time. The game can include multiple levels. As the levels increase, the number of balloons floating on the screen increases, and the floating speed also becomes faster and faster, and the difficulty of the game gradually increases.

[0068] In addition, this device may further include a monitor for monitoring. The training content of the strabismus training module and the eye movement points of the strabismic eye and / or the eye movement points of the non-strabismic eye can be displayed on the monitor for monitoring in real time, so that doctors or family members can understand the content seen by the patient and the training effect in real time.

[0069] For some strabismic patients, the strabismic eye is also amblyopic at the same time. This device may further include a suppression module, which suppresses the image corresponding to the non-strabismic eye in the display module. The suppression method is to blur all or part of the image, reduce the display resolution, darken the brightness, or reduce the contrast, and the suppression degree can be adjusted to make the two eyes in the visual acuity balance range. For example, after suppressing the image seen by the non-strabismic eye by means of Gaussian blur, when looking at the visual acuity chart displayed on the display module with each eye separately, the strabismic and amblyopic eye sees a clear visual acuity chart, while the non-strabismic eye sees a Gaussian-blurred visual acuity chart. In this embodiment, the blur degree when the visual acuities of the two eyes are equal is taken as the suppression degree during training.

[0070] If the patient has alternating strabismus, any one eye can be designated as the strabismic eye and the other eye as the non-strabismic eye, and this device can also be used for visual training.

[0071] In addition to performing strabismus training through a display device such as a polarized display that can separate the left and right eyes, the strabismus training prism diopter can also be calculated according to the W x value calculated in the previous steps. Let the strabismus training prism diopter be L1, and L1 = 100×W x ÷Z0. In this way, the patient can wear a prism with a prism diopter of L1 in daily life and perform strabismus visual training on the basis of maintaining fusion vision by watching real objects, ordinary TVs, and ordinary monitors.

[0072] (5) Recalculate the image displacement range for strabismus training after a period of time

[0073] According to the above steps, after the patient has performed strabismus training for a period of time, for example, after insisting on training for one month, the strabismus degree may have decreased. At this time, methods such as the prism and cover test can be used to retest the strabismus prism diopter of the patient, and the value of S1 can be recalculated according to the new strabismus prism diopter; then the value of P1 can be retested and the value of W x can be recalculated; then the new value of W x can be used for the strabismus training module to perform strabismus training. And the new value of L1 can be calculated according to the new value of W x as the new strabismus training prism diopter. This process can be repeated multiple times, and the W xThe value gradually decreases until finally, even without wearing the prism, the patient can have normal binocular fusion vision without strabismus in real life, thus completing the visual training for strabismus.

[0074] Embodiment 2

[0075] In this embodiment, the display module, the image capture and processing module, the calibration module, and the eye movement point analysis module are the same as those in Embodiment 1. Since the strabismus direction and the strabismus prism diopter of the patient are known, the method for calculating the displacement range of the strabismus training image in the strabismus training image displacement range calculation module is different. In this embodiment, the known strabismus direction of the patient is exotropia of the right eye, and the strabismus prism diopter L0 of the strabismus eye is 15 prism diopters; and the distance between the two eyes and the display module is known to be Z0, and Z0 is 60 cm in this embodiment. Specifically, the displacement range of the strabismus training image is calculated through the following steps:

[0076] (a) Display Image 1 visible only to the left eye, which is the visual target A, in front of the subject being tested, and let the subject fixate on the visual target; additionally, display Image 2 visible only to the right eye, which is the visual target B. The visual target B and the visual target A are of the same size and shape. The visual target B is only visible to the right eye, and the direction of the line connecting the display position of the visual target B and the display position of the visual target A is the direction of strabismus of the strabismus eye. Since the right eye is exotropic, the visual target B is located directly to the right of the visual target A. The initial distance P0 between the visual target B and the visual target A is (Z0×L0) / 100. Substituting the values of Z0 and L0, P0 = 9 cm can be calculated. Record the position of the visual target B at this time as the initial position S0 of the visual target B. If the strabismus patient has binocular fusion vision function, then at this time, the visual target A is imaged on the fovea centralis region of the left eye retina, and the visual target B is imaged on the fovea centralis region of the right eye retina. The brain fuses the images of the two eyes into a single image, and subjectively, only one visual target will be seen.

[0077] (b) Gradually move the visual target B in the direction towards the visual target A. During the movement, define P as the distance between the visual target B and the initial position S0 of the visual target B, define E as the distance between the eye movement point of the strabismus eye and the eye movement point of the non-strabismus eye, define G as the distance between the visual target B and the visual target A, that is, G = P0 - P, define D = |E - G|, and record the values of D changing with P.

[0078] (c) Set a threshold D0, and find the maximum P value P1 corresponding to D ≤ D0.

[0079] (d) The displacement range of the strabismus training image is: the displacement distance W of Image 2 relative to Image 1 x Between P0 and (P0 - P1), that is, (P0 - P1) < W x < P0, and the direction of the displacement of Image 2 relative to Image 1 is the direction of strabismus.

[0080] In this embodiment, except that the method for calculating the displacement range of the strabismus training image is different from that in Embodiment 1, other steps and the strabismus training method are the same as those in Embodiment 1.

[0081] Embodiment 3

[0082] For the display module and the image capture and processing module in the present invention, in addition to the device designed in Embodiment 1, the following methods can also be adopted: (1)

[0084] The display module includes a polarized display that can emit linearly polarized light. The polarized display can emit linearly polarized light in the horizontal direction or in the vertical direction. The display module also includes two polarizers. The left polarizer is located between the left eye and the polarized display, and the right polarizer is located between the right eye and the polarized display. The left polarizer can transmit linearly polarized light in the horizontal direction and cannot transmit linearly polarized light in the vertical direction. The right polarizer can transmit linearly polarized light in the vertical direction and cannot transmit linearly polarized light in the horizontal direction. When the display device displays an image composed only of linearly polarized light in the horizontal direction, the left eye can see the image through the left polarizer, and the right eye cannot see the image through the right polarizer. When the polarized display displays an image composed only of linearly polarized light in the vertical direction, the right eye can see the image through the right polarizer, and the left eye cannot see the image through the left polarizer. The image capture and processing module can capture the image of the left eye through the left polarizer and can capture the image of the right eye through the right polarizer. (2)

[0086] The display module is a naked-eye 3D display that can display an image visible only to the left eye or an image visible only to the right eye. (3)

[0088] The display module includes a display that can emit green visible light with a wavelength of 530 nm or red visible light with a wavelength of 670 nm. The display module also includes two filters. The left filter is located between the left eye and the display, and the right filter is located between the right eye and the display. The left filter can transmit green light with a wavelength of 530 nm but does not transmit red light with a wavelength of 670 nm. The right filter can transmit red light with a wavelength of 670 nm but does not transmit green light with a wavelength of 530 nm. The left eye can see the image composed of green light with a wavelength of 530 nm displayed by the display through the left filter and cannot see the image composed of red light with a wavelength of 670 nm displayed by the display module. The right eye can see the image composed of red light with a wavelength of 670 nm displayed by the display through the right filter and cannot see the image composed of green light with a wavelength of 530 nm displayed by the display. The image capture and processing module can capture the image of the left eye through the left filter and can capture the image of the right eye through the right filter. (4)

[0090] The display module includes a shutter display device and automatic shutter lenses. The automatic shutter lenses include a left shutter lens and a right shutter lens. The left shutter lens is located between the left eye and the shutter display device, and the right shutter lens is located between the right eye and the shutter display device. When the shutter display device displays an image visible only to the left eye, the left shutter lens opens and the right shutter lens closes, and at this time only the left eye can see the image. When the shutter display device displays an image visible only to the right eye, the right shutter lens opens and the left shutter lens closes, and at this time only the right eye can see the image. (V)

[0092] The display module is a VR (Virtual Reality) device. The left eye can only see the image displayed on the left eye display screen of the VR device, and the right eye can only see the image displayed on the right eye display screen of the VR device. The image shooting and processing module includes a micro camera, which shoots at a distance close to the eyes inside the VR, and at least one camera shoots for each eye.

[0093] Embodiment 4

[0094] In addition to using the binocular split-view display device in the previous embodiments for strabismus training, a common display device can also be used to help the patient select a prism that is both smaller than the actual strabismus degree and within the binocular fusion range for strabismus training in daily life. The specific steps are as follows:

[0095] A strabismus training device includes a display module, an image shooting and processing module, a calibration module, an eye movement point analysis module, a strabismus training prism degree range calculation module, a set of prisms with different strabismus degrees, an eye mask, and also includes an electronic computer. The image processing algorithm of the image shooting and processing module, the calibration module, the eye movement point calculation module, and the eye movement point analysis module are all programs running on this electronic computer. In order to further improve the clarity of the images taken by the image shooting and processing module and reduce the eye movement test error caused by head movement, a head fixing bracket is used for head fixing in this embodiment.

[0096] In this embodiment, the display module is a common monitor. When the calibration module performs monocular calibration on the left eye, the right eye can be covered with the eye mask. When calibrating the right eye, the left eye can be covered with the eye mask.

[0097] The image shooting and processing module and the eye movement point calculation module are the same as those in Embodiment 1.

[0098] The function of the strabismus training prism degree range calculation module is to help the patient select a prism that is both smaller than the actual strabismus degree and within the binocular fusion range.

[0099] Taking the strabismus training of a patient with exotropia of the right eye as an example, the specific process is as follows:

[0100] (1) The patient sits in front of this testing device. First, without wearing the prism, place the chin on the head fixation bracket and direct the eyes towards the monitor. The distance between the two eyes and the monitor is 60 cm. The image capture and processing module continuously captures images containing the binocular region.

[0101] (2) Calibration

[0102] During monocular calibration, cover the other eye with an eye patch. After calibration, the eye movement point calculation module can calculate the coordinates of the left eye movement point according to the left eye image and the left eye calibration function, and calculate the coordinates of the right eye movement point according to the right eye image and the right eye calibration function.

[0103] (3) Strabismus training image displacement range calculation module

[0104] In this embodiment, the tested person is a patient with exotropia of the right eye, and the known strabismus prism diopter of the right eye is L0. The strabismus training prism diopter range is calculated through the following steps:

[0105] (a) Display a visual target visible to both eyes directly in front of the tested person and let the tested person fixate on the visual target; at this time, let the patient wear a prism on the right eye with a prism diopter of L0. Since the prism diopter at this time is exactly equal to the prism diopter of the right eye, after the refraction of the prism by the straight line where the visual axis of the patient's right eye is located, it exactly falls on the visual target. At this time, the recorded left eye movement point and right eye movement point will also both fall on the visual target. In actual measurement, due to measurement errors or the jitter of the eyes themselves, etc., even if the left eye movement point and right eye movement point may not completely coincide with the visual target, they will be within a very small area near the visual target, generally within an error range of about 1° visual angle.

[0106] (b) Gradually reduce the prism diopter of the strabismus eye prism. Let the prism diopter of each newly replaced prism be L, define ΔL = (L0 - L), define F as the distance between the movement point of the strabismus eye and the movement point of the non-strabismus eye, and record the value of F changing with ΔL. Figure 4 It is a schematic diagram showing the change of the F value with the ΔL value as the prism diopter changes.

[0107] (c) For a squint eye, since the image capture and processing module captures the eye image of the squint eye through a prism, the recorded eye movement points are also the intersections of the visual axis refracted by the prism and the display plane. If the squint eye can still maintain binocular fusion vision when looking at the visual target through the prism, the eye movement points of the squint eye will also fall on the visual target or within a certain threshold near the visual target. Set a threshold F0. F0 can be an angle of view corresponding to a distance on the display plane of the display module between 2° and 5° of the angle of view. In this embodiment, F0 is set to 3 cm corresponding to 3°; another way to set the value of F0 is to connect the values of F changing with ΔL with line segments. In the line graph of F changing with ΔL, F0 is the value of F corresponding to when the slope of the broken line changes from less than 1 to greater than or equal to 1. Find the maximum value of ΔL, denoted as ΔL1, corresponding to F ≤ F0; and the value of L at this time can be calculated and denoted as L min 。

[0108] (d) From the above steps, it can be calculated that the range of the squint training prism diopter is: Let the squint training prism diopter be L x ,L x ranges from L min <L x <L0. Selecting the prism diopter within this range can produce binocular fusion vision. And the prism diopter within this range is less than the squint prism diopter, which helps the patient gradually reduce the squint degree through visual training. If the value of L x is selected too close to L min , at the verge of fusion break-up, the patient will easily feel visual fatigue; if the value of L x is selected too close to L0, the effect of gradually reducing the squint degree through visual training may be slow. In the actual use process, the doctor can select a suitable value of L min for the patient between L x and L0 according to the specific situation and usage feedback of the patient. Generally, L x can be set as a fixed value between (L min + 0.1×ΔL1) and (L0 - 0.1×ΔL1) according to the training needs, as the prism diopter for squint visual training. In this embodiment, L x = (L0 + L min ) / 2 is set as the squint training prism diopter. In this way, it can not only ensure that the patient's vision is not easily fatigued and enable the patient to adhere to the training for a long time, but also be at a certain distance from the "comfortable zone" corresponding to the squint degree, so that the patient can reduce the squint degree more quickly through training.

[0109] (IV) Squint training

[0110] After determining the squint training image displacement range and selecting the squint training prism diopter L x according to the foregoing steps, squint training can be carried out.

[0111] The strabismus training content can be in the following ways:

[0112] The strabismus training module is a program running on a computer, and the training content is static images, or dynamic videos and animations displayed on a display device. The prism diopter of the prism worn by the strabismic eye is L x .

[0113] The strabismus training module is a program running on a computer, and the training content is an interactive game. The interactive content in the game can be controlled by the eye movement points for real-time interaction. The prism diopter of the prism worn by the strabismic eye is L x .

[0114] In addition, this device can also include a monitor display. The training content of the strabismus training module, the eye movement points of the strabismic eye, and / or the eye movement points of the non-strabismic eye can be displayed on the monitor display in real time, so that doctors or family members can understand the content seen by the patient and the training effect in real time.

[0115] It is also possible to wear a prism with a prism diopter of L x by the strabismic eye in daily life for strabismus training by watching real objects in daily life, such as reading, threading beads, watching TV, etc.

[0116] Some strabismic patients have amblyopia in their strabismic eyes at the same time. This device can also include a suppression module, which suppresses the non-strabismic eye. For example, let the non-strabismic eye wear a lens with a semi-transparent plastic film pasted on it, or use drugs such as atropine to reduce the vision of the non-strabismic eye, so that the two eyes are in the visual acuity balance range. The visual acuity balance range means that the visual acuity of the two eyes is made equal or similar by suppression when looking at the visual acuity chart.

[0117] (V) Recalculate the range of strabismus training prism diopter after a period of time

[0118] According to the above steps, after the patient has undergone strabismus training for a period of time, for example, after insisting on training for one month, the strabismus degree may have decreased. At this time, the strabismus prism diopter L0 of the patient can be retested using classic methods such as the prism and cover test, and the value of ΔL1 can be recalculated according to the new strabismus prism diopter; then the new L min value is obtained, and the new L min value is used to calculate the new L x value as the strabismus training prism diopter, and the new L x value is used for strabismus training by the strabismus training module. This process can be repeated multiple times, and the L x value gradually decreases until finally no prism is needed and there is no strabismus and normal fusion vision in real life, thus completing the visual training of strabismus.

Claims

1. A strabismus training device, characterized in that, Comprising: A display module; An image capturing and processing module, including at least one camera, capable of continuously capturing images of the left eye and the right eye; A calibration module for separately performing monocular calibration on the left eye and the right eye; when performing monocular calibration on the left eye, only the left eye can see the calibration target displayed on the display module; when performing monocular calibration on the right eye, only the right eye can see the calibration target displayed on the display module; obtaining a left-eye calibration function through left-eye monocular calibration, and obtaining a right-eye calibration function through right-eye monocular calibration; An eye movement point calculation module, after the left-eye calibration and the right-eye calibration are completed, calculating the coordinates of the left-eye movement point according to the left-eye image and the left-eye calibration function, and calculating the coordinates of the right-eye movement point according to the right-eye image and the right-eye calibration function; A strabismus training prism diopter range calculation module, assuming that one of the two eyes is a strabismic eye and the other is a non-strabismic eye, the strabismus direction of the strabismic eye is known, and the known strabismus prism diopter is L0; Calculating the strabismus training prism diopter range through the following steps: (a) Display a target visible to both eyes directly in front of the subject, and let the subject fixate on the target; at this time, the prism diopter of the prism worn by the strabismic eye is L0; (b) Gradually reduce the prism diopter of the prism of the strabismic eye, assuming that the prism diopter of each newly replaced prism is L, defining ΔL=(L0 - L), defining F as the distance between the eye movement point of the strabismic eye and the eye movement point of the non-strabismic eye, and recording the value of F changing with ΔL; (c) Set a threshold F0, find the maximum value of ΔL, denoted as ΔL1, corresponding to F ≤ F0; and the prism power L value of the prism corresponding at this time can be obtained and denoted as L min , where the threshold F0 is determined by one of the following two methods: Method 1: The threshold F0 is the distance corresponding to an angle between 2° and 5° of view on the display plane of the display module; Method 2: Establish a rectangular coordinate system, the two coordinate axes of the rectangular coordinate system respectively correspond to the F and the ΔL, take the value of the F and the corresponding value of the ΔL as the coordinate points in the rectangular coordinate system, connect the coordinate points to form a line graph, then the threshold F0 is the value of the F corresponding to when the slope of the line segment in the line graph changes from less than 1 to greater than or equal to 1; (d) The range of the strabismus training prism diopter is: Let the strabismus training prism diopter be L x , L x The value range of is L min <L x <L0; During the strabismus training, let the strabismus eye wear a prism with a prism diopter of L x for strabismus training.

2. The strabismus training device according to claim 1, characterized in that, Set L x to any fixed value between (L min + 0.1 × ΔL1) and (L0 - 0.1 × ΔL1) as the strabismus training prism diopter.

3. The strabismus training device according to claim 1, characterized in that, Set L x =(L0 + L min ) / 2, as the strabismus training prism diopter.

4. The strabismus training device according to claim 1, wherein If the strabismic eye is also an amblyopic eye, it further includes a suppression module, and the suppression module suppresses the non-strabismic eye to make the two eyes in the visual acuity balance range.

5. The strabismus training device according to claim 1, characterized in that It further includes a strabismus training module which is controlled by a program, and the training content is static images or dynamic videos displayed on a display device; the prism diopter of the prism worn by the strabismic eye is L x .

6. The strabismus training device according to claim 1, characterized in that It further includes a strabismus training module which is controlled by a program. The training content is an interactive game displayed on a display device, and the interactive content in the game can be controlled by the eye movement points for real-time interaction; the prism diopter of the prism worn by the strabismus eye is L x .

7. The strabismus training device according to claim 5 or 6, characterized in that, It further includes a monitor display, and the training content of the strabismus training module and the eye movement points of the strabismic eye and / or the eye movement points of the non-strabismic eye can be displayed on the monitor display in real time.

8. The strabismus training device according to claim 1, characterized in that, It further includes a strabismus training module. The way of strabismus training is that in daily life, the strabismic eye wears a prism with a prism diopter of L x and conducts strabismus training by observing real objects.

9. The strabismus training device according to claim 1 or 8, characterized in that, After a period of training, re-test the patient's strabismus prism diopter, and re-measure the value of ΔL1 according to the new strabismus prism diopter; then obtain the new L min value, and calculate the new L min value according to the new L x value as the strabismus training prism diopter; And use the new L x value for the strabismus training module to perform strabismus training; This process can be cycled multiple times.

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