A method for screening visual function

Abstract

The present invention provides a visual function screening method, which belongs to the field of visual function testing, integrates vision test, refraction test and visual function test into one device, can simulate far vision test in a limited space, reduce the transportation cost of screening equipment and the demand for screening work manpower, and save students' time for switching between different devices, making campus screening more convenient. The present invention occupies a small space, has high flexibility, and improves the efficiency of screening.

Description

Technical Field

[0001] The invention belongs to the field of visual function testing and relates to a visual function screening method. Background Art

[0002] With the increasing incidence of myopia among young people and the inclusion of youth eye health in national policies, eye health screening in schools has become more popular and valued.

[0003] Previously, for a long time, only vision was checked for eye screening. As people pay more attention to the eye health of teenagers, some areas with conditions have gradually added refractive screening. Currently, the commonly used refractive screening tools on the market include purely objective examination tools such as automatic computer ophthalmometers and refractive screeners. The advantage of this type of equipment is that the examination is relatively convenient and quick, and the disadvantage is that the examination results are greatly affected by the adjustment of teenagers, and the deviation may be as high as 3.00D or even more, which greatly affects the accuracy of judgment. Especially for children who do not have myopia and whose actual refractive power is mainly distributed in 0-+3.50D, the refractive power data obtained through computer optometry or refractive screening will be concentrated between 0-1.00D, and it is impossible to distinguish their myopia risks well, making the myopia prevention work not accurate enough. In addition, if only checking refractive power and visual acuity cannot fully assess the health of the eyes, more and more studies have shown that changes in some visual function indicators have a warning effect on the occurrence and development of myopia. Therefore, in addition to checking visual acuity and refractive power, visual function examination indicators should also be added.

[0004] In addition, existing eye health examination equipment, such as those on campus, often has one tool for vision examination and another tool for refraction examination. Each examination uses different tools, and vision examination also requires a distance of 5 meters, which requires a larger floor space and more staff. Summary of the invention

[0005] The problem to be solved by the present invention is to provide a visual function screening method, which can simulate long-distance visual marks in a smaller space, occupies less space, has more complete functions, and improves screening efficiency.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a visual function screening method, comprising the following steps:

[0007] S1. Based on the best visual acuity of the examinee, take the sight marks of 1-10 lines upward as the initial inspection sight marks;

[0008] S2. Based on the standard refraction of the screened person's age group, add distance adjustment spherical power and fog vision spherical power as the initial inspection lens;

[0009] S3, requiring the examinee to identify the sight mark. When the examinee cannot identify the sight mark, the negative spherical lens is increased or the positive spherical lens is reduced with a large step length ξD; when the examinee can identify the sight mark, the size of the sight mark is adjusted to a smaller sight mark in the eye chart, and this step is repeated until the preset standard vision is reached;

[0010] S4, the lens reduces the negative spherical mirror by 1ξD or more, or increases the positive spherical mirror by 1ξ or more;

[0011] S5. Ask the examinee to identify the sight mark. If the examinee cannot identify the sight mark, increase the negative spherical mirror or decrease the positive spherical mirror in a small step size ε greater than 0D and less than 1ξD, and repeat this step until the examinee can identify the sight mark.

[0012] S6. After the examination is completed, the spherical power at the end of the examination is used to adjust the distance and the spherical power is used as the result of the refractive screening.

[0013] Further, in step S1, the best visual acuity refers to the visual acuity corresponding to the smallest row of visual marks on the visual acuity chart that can be seen, and the visual acuity charts 1-10 rows above are taken. The visual acuity chart referred to includes various types of visual acuity charts, and the size change of the 10 rows of visual marks is equivalent to the visual acuity value of the five-point visual acuity method minus 1.0.

[0014] Furthermore, in step S2, a convex lens is added in front of the eye to be inspected so that parallel light rays are focused in front of the retina. If the eyeball uses accommodation, the image will move forward, farther away from the retina, and the image will be more blurred. In order to see distant objects clearly, the eye to be inspected is forced to automatically relax its accommodation gradually, so that the focused image moves closer to the retina, the image becomes clear, and the eye to be inspected automatically relaxes its accommodation.

[0015] Furthermore, in step S2, the calculation formula for the diopter D of the adjustment spherical lens that needs to be added in front of the eye is:

[0016] D=1 / aL-1 / dL+θ

[0017] aL: actual measurement distance used for simulation, in meters;

[0018] dL: the test distance you want to simulate, in meters;

[0019] θ: adjustment coefficient, unit D;

[0020] Furthermore, in step S2, the calculation formula of the adjustment ratio a of the visual mark size that needs to be added in front of the eyes is:

[0021] a=dL / (aL*(1-d*D))

[0022] aL: actual measurement distance used for simulation, in meters;

[0023] dL: the test distance you want to simulate, in meters;

[0024] d: lens eye distance, unit: m.

[0025] Further, a screening device is used, including:

[0026] A lens control board, used for transmitting lens rotation position instructions to the eyepiece disc;

[0027] The eyepiece disc transmits the lens rotation position instruction to the lens control board;

[0028] The system core board is used to transmit the instructions of rotating the lens to the lens control board;

[0029] The lens control board transmits the lens switching completion instruction to the system core board;

[0030] The system core board is used to transmit image signals to the visual target display screen, and the buttons transmit key commands to the system core board.

[0031] Furthermore, a plurality of lenses are arranged on the eyepiece disc, and the lens specifications are replaceable. The lenses include but are not limited to screening the following functions: vision, refraction, and visual function screening, and the sight marks are replaced according to lens requirements.

[0032] Furthermore, the screening instrument includes a human-computer interaction interface for displaying and saving the recorded results.

[0033] Furthermore, the screening instrument comprises a box, the front end of which is provided with an observation window matching both eyes and having an adjustable pupil distance;

[0034] An eyepiece disk corresponding to the observation window is provided inside the box, and the number of the eyepiece disks is a plurality of parallelly arranged, the eyepiece disk is rotatably connected to the moving frame, and a plurality of lenses are arranged on the eyepiece disk, and the lenses rotate with the eyepiece disk, and in a stopped state, the lenses are arranged corresponding to the observation window;

[0035] A dark box is provided in the box body, the front end of the dark box corresponds to the two observation windows, and the rear end is provided with a screen for imaging;

[0036] The box is provided with a control panel for controlling screen content display and sound output.

[0037] Furthermore, a support frame is provided at the front end of the box body, an adjustment rod is provided on the support frame, the adjustment rod moves forward and backward relative to the eyepiece plate, and a baffle is provided at the front end of the adjustment rod for supporting the forehead of the tester;

[0038] A loudspeaker is provided in the box for outputting the audio signal of the screen, a plurality of holes are provided in the area of ​​the box corresponding to the loudspeaker, and buttons are provided on both sides of the front end of the box for volume adjustment, selection and feedback;

[0039] The rear end of the box is provided with a power input port for powering the electrical components, several USB interfaces for external devices or programs, a LAN port for connecting to a network cable, a power switch, and the front end of the box is provided with a button for the tester to input a signal, and the button is electrically connected to the control panel;

[0040] The lower front end of the box is provided with an avoidance area for avoiding the lower end or other facial organs of the tester, and the surface of the button fixed on the side of the box is designed as an inclined surface.

[0041] Compared with the prior art, the present invention has the following advantages and positive effects.

[0042] 1. The refractive screening method of the present invention adopts a rapid subjective examination method. The examination result is not as high as that of traditional manual optometry (it cannot reach the examination accuracy of glasses fitting), but the accuracy of its equivalent spherical power examination is higher than that of objective examination result, which can reduce the deviation of the refractive examination result caused by the influence of accommodation in objective optometry, so that the refractive power distribution of children who are not yet myopic can be clearer;

[0043] 2. This application integrates vision testing, refraction testing, and visual function testing into one device, which reduces the transportation cost of screening equipment and the demand for screening manpower, and saves students' time switching between different devices, making campus screening more convenient;

[0044] 3. The present invention adds human-computer interaction and automatically saves the inspection results during the inspection process, making the inspection feedback faster and saving the time of on-site recording;

[0045] 4. The vision screening of this application adopts optical principles, so that long-distance sight marks can be simulated in a smaller space without the actual distance of 5 meters, which shortens the inspection distance, makes the entire device smaller, and is more convenient for on-site use.

[0046] 5. The screening device used can be set with a variety of lenses for combination, integrating multiple functions in one, and its appearance is less than 43 cm, taking up little space, easy to carry, and has a wide range of application scenarios. It can be used by doctors, schools and families, and its appearance is more beautiful.

[0047] 6. During the use of the screening instrument, the tester operates according to the prompt sound, which reduces the professional requirements for the operator and makes the operation more convenient. The tester operates according to the voice prompt, which makes it easier to achieve human-computer interaction and is conducive to home use. It also integrates the optical structure and content display structure of large equipment, with a more compact internal structure. It also has a sound module and control button structure that facilitates human-computer interaction, allowing more families to train and improve their visual functions more conveniently. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0049] Figure 1 It is a schematic diagram of the results of a screening instrument used in a visual function screening method of the present invention;

[0050] Figure 2 It is a schematic diagram of the structure of the present invention for visual function screening, inspection and training;

[0051] Figure 3 It is a schematic diagram of the structure of the present invention for visual function screening, inspection and training without the front view of the box;

[0052] Figure 4 The present invention Figure 3 Detailed drawing of Part A;

[0053] Figure 5 It is a schematic diagram of the structure of the present invention for visual function screening, inspection and training without the box body and dark box;

[0054] Figure 6 It is a schematic diagram of the structure of the present invention for visual function screening, inspection and training without the rear view of the box.

[0055] Reference numerals:

[0056] 1. Box body; 11. Indicator light; 12. Foot pad; 13. Hole; 2. Eyepiece plate; 21. Driving wheel; 3. Observation window; 31. Protective frame; 4. Moving frame; 41. Moving seat; 42. Lead screw; 43. Guide rod; 46. Positioning plate; 5. Motor; 6. Dark box; 7. Control panel; 8. Loudspeaker; 9. Power input port; 10. Button; 20. Baffle; 201. Adjustment rod; 202. Driving rod; 203. Active bevel gear; 204. Driven bevel gear; 205. Fixed plate. DETAILED DESCRIPTION

[0057] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0058] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate relative positions or positional relationships, which are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0059] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0060] The specific embodiments of the present invention are described in detail below.

[0061] The purpose of subjective refraction is to obtain accurate glasses prescription, including accurate spherical power, cylindrical power and axial direction, and the examination time is relatively long; the purpose of subjective refractive screening is to obtain the overall refractive situation (that is, equivalent spherical power) in a shorter time, especially for children who are not myopic, so that the refractive power can be differentiated to a certain extent.

[0062] Since the refractive range of the key population for subjective refractive screening is relatively uniform, through clever process design, no distinction is made between spherical power and cylindrical power, and the overall refractive condition can be tested, while greatly improving the inspection speed.

[0063] The principle of the simulated distance vision test is as follows.

[0064] The light emitted (or reflected or refracted) by a nearby object is a divergent light. The divergence of light emitted (or reflected or refracted) by a distant object is lower than that of a nearby object. The light emitted (or reflected or refracted) by an infinitely distant object is a parallel light. When the eyes focus on a distant object, the ciliary muscle relaxes and the surface of the lens is flat. When looking at a nearby object, the ciliary muscle contracts, the suspensory ligaments of the lens gradually relax, and the surface of the lens gradually bulges, producing accommodation and increasing the degree of convergence of light. The closer the target object is, the more accommodation the eyes need to use.

[0065] When testing far vision, the eyes use less accommodation power, while when testing near vision, the eyes need to use more accommodation power. The relationship between the target distance (L, unit: m) and the accommodation demand (AD, unit: D) ​​is: AD = 1 / L. If the inspection distance is 5 meters, the accommodation demand is 0.2D, and if the inspection distance is 40cm, the accommodation demand is 2.5D. Therefore, for monocular vision testing, the main difference between far and near vision testing lies in the difference in accommodation demand.

[0066] Spherical lenses have the function of changing the degree of light divergence and convergence. Placing a positive spherical lens in front of the eyes when looking at close objects can converge the light, thereby reducing the adjustment required by the eyes. The degree of light divergence or convergence of a spherical lens can be measured by refractive power, which is expressed in diopters, expressed in D. When a positive spherical lens with a refractive power of +1.00D is added in front of the eyes, the adjustment power of the eyes when looking at close objects can be reduced by 1.00D.

[0067] By placing a corresponding spherical mirror in front of the eyes of the person being examined and adjusting the divergence of light emitted (or reflected or refracted) by close objects, the divergence of light emitted (or reflected or refracted) by distant objects is simulated, thereby measuring far vision in a smaller space and at a shorter distance. At the same time, in order to ensure the consistency of the test sight mark viewing angle, the sight mark needs to be reduced proportionally after the sight mark distance is shortened. At the same time, considering the magnification and reduction effect of the spherical mirror on the image, the size of the sight mark needs to be adjusted to a certain extent.

[0068] The specific calculation formula for the diopter D of the adjustment spherical lens and the adjustment ratio a of the sight mark size that needs to be added in front of the eyes is:

[0069] D=1 / aL-1 / dL+θ

[0070] a=dL / (aL*(1-d*D))

[0071] aL: actual measurement distance used for simulation, in meters;

[0072] dL: the test distance you want to simulate, in meters;

[0073] θ: adjustment coefficient, unit D;

[0074] d: lens eye distance, unit: m.

[0075] Example:

[0076] Assume that you want to simulate 5-meter far vision measurement with a measurement distance of 30 cm, the designed lens-eye distance is 12 mm, and the adjustment coefficient is θ = -0.13D. Then aL = 0.3m, dL = 5m. Then:

[0077] Adjust the spherical lens D = 1 / 0.3-1 / 5-0.13 = 3.00D

[0078] The ratio of sight mark size adjustment a=5 / 0.3*(1-0.012*3)=16.07

[0079] A 3.00D positive spherical lens is placed 12mm in front of the eye and the five-meter sight mark is reduced by 16.07 times as the sight mark for close distance inspection.

[0080] The present invention is a method for screening visual function. The method comprises the following steps:

[0081] 1. The best visual acuity of the person being examined is taken as the basis. The best visual acuity refers to the visual acuity corresponding to the smallest row of sight marks on the visual acuity chart that can be seen. The sight marks of 1-10 rows upwards are equivalent to the visual acuity value of the five-point visual acuity method minus 0.1-1.0, which are used as the initial examination sight marks. The visual acuity chart referred to includes various types of visual acuity charts. The size changes of the 10 rows of sight marks are equivalent to the visual acuity value of the five-point visual acuity method minus 1.0.

[0082] 2. Based on the standard refractive power of the screened person's corresponding age group, add distance adjustment spherical power and fog vision spherical power as the initial lens inspection; the normal range of refractive power for different age groups is explained as follows.

[0083] The eyes begin to develop during the embryonic period, but the vision is still not fully developed when the baby is born. The vision of a newborn baby is only 0.02-0.05 and is highly hyperopic.

[0084] As the baby grows up day by day, his motor ability and range of activities are expanding, and his vision develops to 0.2-0.3;

[0085] As the baby grows and develops, the eyeball becomes larger and the hyperopia reserve value gradually decreases. The vision of a 3-year-old baby has developed to the level of 0.4-0.6, and the axial length of the eye is about 22mm. At this time, the baby is still in a hyperopic state, with a hyperopia reserve of about +3.00D.

[0086] Babies aged 4-5 years old have rapid physical and intellectual development, and their fine discrimination ability will also be greatly improved. Their visual acuity can generally reach 0.6-0.8 or even better. At this time, their hyperopia reserve is about +2.00D-+2.50D.

[0087] At the age of 6 to 7, most children's vision can basically reach 1.0 or even 1.2 or 1.5. At this time, there is still a reserve of hyperopia, about +1.50D to +2.00D;

[0088] By the age of 12, the visual acuity has fully developed to adult visual acuity of 1.0 or even better, and the hyperopia reserve value has basically disappeared, which is about +0.50D.

[0089] Fog vision is a common concept in optometry. When the eye looks at distant objects, the method of adding a moderate convex lens in front of the eye to relax the eye's accommodation is called fog vision technique. The principle is to add a moderate convex lens in front of the eye to be examined so that parallel light rays can be focused in front of the retina. If the eye uses accommodation, the image will move forward, farther away from the retina, and the image will be blurrier. In order to see distant objects clearly, the eye to be examined is forced to automatically and gradually relax its accommodation, so that the focus is closer to the retina and the image becomes clear. Therefore, during subjective optometry, adding a moderate convex lens in front of the eye to be examined can prompt the eye to automatically relax its accommodation, thereby eliminating or reducing the influence of accommodation on the results of refractive examination.

[0090] 3. The examinee is required to identify the sight mark. When the examinee is unable to identify the sight mark, the negative spherical lens is increased or the positive spherical lens is reduced in a large step size ξD. When the examinee is able to identify the sight mark, the size of the sight mark is adjusted to a smaller sight mark in the eye chart. It is preferred to reduce the size of the sight mark in steps greater than or equal to 0.1, and repeat this step until the preset standard vision is reached.

[0091] 4. The lens reduces the negative sphere by 1ξD or more, or increases the positive sphere by 1ξ or more. Preferably, the lens reduces the negative sphere by 1ξD-3ξD, or increases the positive sphere by 1ξ-3ξ, where ξ is the large step length, ε is the small step length, and D is the unit symbol of diopter.

[0092] The traditional method is to increase by 0.25D each time, which is the step length. There is an initial benchmark, and then find the end point, which is the refractive power, and go step by step. Now it is to speed up the screening, and now the pace is faster. Once you cross the end point, you need to step back and then move forward in small steps until you reach the end point and determine a more accurate refractive power. In this method, the so-called end point is a judgment criterion and a reference value.

[0093] 5. Ask the subject to identify the visual mark. If the subject cannot identify the visual mark, increase the negative spherical mirror or decrease the positive spherical mirror in small steps ε that are greater than 0D and less than 1ξD. Repeat this step until the subject can identify the visual mark.

[0094] 6. At the end of the examination, the spherical power at the end of the examination is used to adjust the distance and the spherical power is used as the result of the refractive screening.

[0095] During the entire screening process, a screening instrument is used, including:

[0096] A lens control board, used for transmitting lens rotation position instructions to the eyepiece disc;

[0097] The eyepiece disc transmits the lens rotation position instruction to the lens control board;

[0098] The system core board is used to transmit the instructions of rotating the lens to the lens control board;

[0099] The lens control board transmits the lens switching completion instruction to the system core board;

[0100] The system core board is used to transmit image signals to the visual target display screen, and the buttons transmit key commands to the system core board.

[0101] There are multiple lenses on the eyepiece disc, and the lens specifications are replaceable. The lenses include but are not limited to screening the following functions: vision, refraction, and visual function screening. The sight marks can be replaced according to lens requirements.

[0102] Preferably, the screening instrument includes a human-computer interaction interface for displaying and saving the recorded results.

[0103] The following is a detailed description of the application structure: Figure 2-Figure 6 As shown, the screening instrument comprises a box 1, and the front end of the box 1 is provided with an observation window 3 which matches both eyes and has an adjustable pupil distance;

[0104] An eyepiece disc 2 corresponding to the observation window 3 is provided inside the box body 1. The number of the eyepiece discs 2 is a plurality of eyepiece discs 2 arranged in parallel. The eyepiece discs 2 are rotatably connected to the moving frame. A plurality of lenses are arranged on the eyepiece discs 2. The lenses rotate with the eyepiece discs 2. When the lenses are stopped, they are arranged corresponding to the observation window 3.

[0105] A dark box 6 is provided in the box body 1, the front end of the dark box 6 corresponds to the two observation windows 3, and the rear end is provided with a screen for displaying the content;

[0106] A control panel 7 is provided in the box body 1 for controlling the screen content display and the sound output.

[0107] Preferably, a support frame is provided at the front end of the box body 1, and an adjusting rod 201 is provided on the support frame. The adjusting rod 201 moves forward and backward relative to the eyepiece plate 2, and a baffle 20 is provided at the front end of the adjusting rod 201 for supporting the forehead of the tester; preferably, a fixing plate 205 is provided at the upper end of the support frame, a driving rod 202 is fixedly provided on the fixing plate 205, an active bevel gear 203 is provided at the lower end of the driving rod 202, a driven bevel gear 204 is provided on the adjusting rod 201, the active bevel gear 203 is meshed with the driven bevel gear 204, and the upper end of the driving rod 202 protrudes from the upper end surface of the box body 1, so as to realize the front and rear adjustment of the baffle 20 and meet the application needs of different testers.

[0108] Preferably, the outer ring of each eyepiece disc 2 is a gear structure, and each eyepiece disc 2 is matched with a driving wheel 21. Each driving wheel 21 corresponds to a motor 5. The motor 5 is fixed on the mobile frame 4 to realize the independent rotation of each eyepiece disc 2. A combination of multiple lenses can be realized to meet the needs of multiple functional tests and training.

[0109] Preferably, the observation window 3 is arranged on the protective frame 31, the protective frame 31 is fixed on the upper end of the mobile frame 4, and the lower end of the mobile frame 4 is fixed on the mobile seat 41: a lead screw 42 is provided at the lower end of the interior of the box body 1, and the mobile seat 41 cooperates with the lead screw 42 as a nut, and the motor 5 drives the lead screw 42 to rotate and drives the two mobile seats 41 to move at the same time. The two mobile seats 41 are symmetrically arranged relative to the center line of the box body 1, adopting a symmetrical structure, balanced force, and convenient and quick adjustment.

[0110] Preferably, a plurality of positioning plates 46 are vertically provided on the lower end surface of the box body 1, and the motor 5 that drives the screw 42 is fixed on the positioning plate 46 at one end. The motor 5 drives the screw 42 to rotate through a gear transmission structure. A guide rod 43 is arranged between the positioning plates 46, and the axis of the guide rod 43 is arranged parallel to the axis of the screw 42. The moving seat 41 slides relative to the guide rod 43 through a copper sleeve or a sliding bearing, thereby ensuring the movement accuracy of the moving seat 41 and realizing the stability of the adjustment of the moving seat 41.

[0111] Preferably, a loudspeaker 8 is provided in the box 1 for outputting the audio signal of the screen. A plurality of holes 13 are provided in the area of ​​the box 1 corresponding to the loudspeaker 8. The plurality of holes 13 are beneficial to the amplification and transmission of sound as well as the heat dissipation of components inside the box 1. A volume adjustment button is provided at the front end of the box 1 for operations such as volume adjustment, selection, and feedback. The tester adjusts and sets the volume according to his own situation. More preferably, the loudspeaker is recessed for easy hand gripping during transportation.

[0112] Preferably, a power input port 9 is provided at the rear end of the box 1 to supply power to the electrical components, a button 10 is provided at the front end of the box 1, and the button 10 is electrically connected to the control board 7. The rear end of the box 1 also has several USB interfaces for external devices, a LAN port for connecting to a network cable, and a power switch for controlling the power on or off.

[0113] Preferably, an indicator light 11 displaying the working status is provided at the upper end of the box body 1, which is aesthetically pleasing and allows the working status to be checked in real time. For convenience, a plurality of shock-absorbing feet 12 are provided at the lower end of the box body 1 to improve the stability of placement, protect the internal parts, and increase the service life of the entire structure.

[0114] Preferably, a avoidance area is provided at the lower front end of the box 1 to avoid the lower end or other facial organs of the tester, and the surface of the button fixed on the side of the box is designed as a slope to facilitate the user to press the buttons.

[0115] In the actual working process, the box body 1 is placed on a horizontal workbench. The lower front end of the box body 1 is provided with an avoidance area for avoiding the lower end or other facial organs of the tester. The upper end is provided with a baffle 20, which is close to the forehead to position the front and back directions of the human face. The tester's eyes correspond to the observation windows 3. For different testers, the distance between the two observation windows 3 is adjusted by the motor 5 to meet the test needs of different testers. Then the tester observes the display on the screen through the dark box 6, operates according to the steps and instructions according to the content transmitted by the loudspeaker 8, presses the corresponding button 10, and records the test results in time. Since each eyepiece disc 2 can be rotated, the observation window 3 can correspond to multiple lenses of different specifications, complete tests of multiple functions, integrate multiple test functions, and has a compact structure, a maximum length of about 43 cm, and is easy to operate. It can be operated according to the prompts, reducing dependence on professionals.

[0116] Example:

[0117] The examinee is 6 years old, with naked eye vision of 5.0, the examination distance is 33cm, and the standard hyperopia reserve is +1.50D~+2.00D. Here, 1.50D is taken as the standard for this age group. The set standard vision is 5.0. The distance adjustment spherical lens is set to +3.00D, the fog vision spherical lens is set to +1.00D, the large step length ξ=1.00D, the small step length ε=0.25D, and the initial examination sight mark is set to 4 lines above the best vision.

[0118] According to the best visual acuity of the examinee, 4.6 in the 4 rows above is used as the initial inspection sight mark;

[0119] 5.50D (1.50D+3.00D+1.00D) was used as the spherical power for the initial examination;

[0120] The examinee is required to identify the sight mark. When the examinee cannot identify the sight mark, the spherical lens is -1.00D. When the examinee can identify the sight mark, the size of the sight mark is reduced in steps of 0.1. This step is repeated until the sight mark reaches 5.0. If the degree of the sight mark can still be identified, the switching of the sight mark is stopped. Assume that when the lens is +3.00D, the examinee can see the 5.0 sight mark for the first time. At this time, this step ends and goes to the next step.

[0121] The lens increases the spherical lens by a large step size of ξ=1.00D to +4.00D, and the visual mark is 5.0. At this time, the examinee cannot recognize it. Then, the positive spherical lens is reduced to +3.75D in a small step size of ε=0.25. At this time, the examinee can recognize the 5.0 visual mark.

[0122] At the end of the examination, the refractive screening result after adjusting the distance spherical power and fog vision spherical power was -0.75D.

[0123] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A method for screening visual function, characterized in that: The following steps are included: S1. Based on the best visual acuity of the examinee, take the sight marks of 1-10 lines upward as the initial inspection sight marks; S2. Based on the standard refraction of the screened person's age group, add distance adjustment spherical power and fog vision spherical power as the initial inspection lens; S3, requiring the examinee to identify the sight mark. When the examinee cannot identify the sight mark, the negative spherical lens is increased or the positive spherical lens is reduced with a large step length ξD; when the examinee can identify the sight mark, the size of the sight mark is adjusted to a smaller sight mark in the eye chart, and this step is repeated until the preset standard vision is reached; S4, the lens reduces the negative spherical lens by 1ξD or more, or increases the positive spherical lens by 1ξD or more; S5. Ask the examinee to identify the sight mark. If the examinee cannot identify the sight mark, increase the negative spherical mirror or decrease the positive spherical mirror by a small step length εD greater than 0D and less than 1ξD, and repeat this step until the examinee can identify the sight mark. S6. After the examination is completed, the spherical power at the end of the examination is adjusted for distance adjustment and the result of the refractive screening is taken as the result; In step S2, the calculation formula for the diopter D of the adjustment spherical lens that needs to be added in front of the eye is: D=1 / aL-1 / dL+θ aL: actual measurement distance used for simulation, in meters; dL: the test distance you want to simulate, in meters; θ: adjustment coefficient, unit: D; In step S2, the calculation formula of the adjustment ratio a of the sight mark size that needs to be added in front of the eyes is: a= dL / ( aL*(1-d*D)) aL: actual measurement distance used for simulation, in meters; dL: the test distance you want to simulate, in meters; d: lens eye distance, unit: m; Use screening instruments, including: A lens control board, used for transmitting lens rotation position instructions to the eyepiece disc; The eyepiece disc transmits the lens rotation position instruction to the lens control board; The system core board is used to transmit the instructions of rotating the lens to the lens control board; The lens control board transmits the lens switching completion instruction to the system core board; The system core board is used to transmit image signals to the visual mark display screen, and the buttons transmit key commands to the system core board; multiple lenses are arranged on the eyepiece plate, and the lens specifications are replaceable. The lenses include but are not limited to screening the following functions: vision, refraction, and visual function screening. The visual marks are replaced according to the lens requirements. The screening instrument includes a human-computer interaction interface for displaying and saving the recorded results.

2. A method for screening visual function according to claim 1, characterized in that: In step S1, the best visual acuity refers to the visual acuity corresponding to the smallest row of sight marks on the visual acuity chart that can be seen, and the sight marks of rows 1-10 are taken upwards. The visual acuity chart referred to includes various types of visual acuity charts. The size change of the 10 rows of sight marks is equivalent to the visual acuity value of the five-point visual acuity method minus 1.

0.

3. A method for screening visual function according to claim 1, characterized in that: In step S2, a convex lens is added in front of the eye to be inspected to focus parallel light rays in front of the retina. If the eyeball uses accommodation, the image will move forward, farther away from the retina, and the image will be more blurred. In order to see distant objects clearly, the eye to be inspected is forced to automatically relax its accommodation gradually, so that the focused image moves closer to the retina, the image becomes clear, and the eye to be inspected automatically relaxes its accommodation.

4. A method for screening visual function according to claim 1, characterized in that: The screening instrument comprises a box, the front end of which is provided with an observation window matching both eyes and having an adjustable pupil distance; An eyepiece disk corresponding to the observation window is provided inside the box, and the number of the eyepiece disks is a plurality of parallelly arranged, the eyepiece disk is rotatably connected to the moving frame, and a plurality of lenses are arranged on the eyepiece disk, and the lenses rotate with the eyepiece disk, and in a stopped state, the lenses are arranged corresponding to the observation window; A dark box is provided in the box body, the front end of the dark box corresponds to the two observation windows, and the rear end is provided with a screen for imaging; The box is provided with a control panel for controlling screen content display and sound output.

5. A method for screening visual function according to claim 4, characterized in that: A support frame is provided at the front end of the box body, and an adjustment rod is provided on the support frame. The adjustment rod moves forward and backward relative to the eyepiece plate, and a baffle is provided at the front end of the adjustment rod for supporting the forehead of the tester; A loudspeaker is provided in the box for outputting the audio signal of the screen, a plurality of holes are provided in the area of ​​the box corresponding to the loudspeaker, and buttons are provided on both sides of the front end of the box for volume adjustment, selection and feedback; The rear end of the box is provided with a power input port for powering the electrical components, a number of USB interfaces for external devices or programs, a LAN port for connecting to a network cable, a power switch, and the front end of the box is provided with a button for the tester to input a signal, and the button is electrically connected to the control panel; The lower front end of the box is provided with an avoidance area for avoiding the lower end or other facial organs of the tester, and the surface of the button fixed on the side of the box is designed as an inclined surface.

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