A rapid intermediate visual dark adaptation function examination method

Abstract

The application discloses a rapid mesopic dark adaptation function examination method, and an examination device mainly comprises an eyeshade, a mesopic visual field assembly, a dark visual mark assembly, a front cover and a headgear. 2 The representative parameters, such as maximum brightness 17 cd / m2, wavelength 540-550 nm and the like, are scientifically set during examination, the dark adaptation time after mesopic visual field stimulation can be accurately obtained, and thus the effective evaluation on the mesopic dark adaptation function is realized.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of optoelectronic technology, and relates to a visual function inspection device and an inspection method. BACKGROUND

[0002] Dark adaptation refers to the phenomenon that when a human eye enters a dark environment from a bright environment or when the illumination of an environment suddenly stops, the human eye cannot distinguish the target in the dark environment and needs a period of time to clearly see the surrounding objects. This is a physiological phenomenon of the human eye and is determined by the sensitivity of the retinal cells of the human eye to weak light and the change of the pupil of the human eye.

[0003] Intermediate vision is the vision produced by the combined action of the retinal cone cells and rod cells when the human eye is in a luminance environment between the bright vision and dark vision adaptation luminance range. For example, the vision produced when a driver or pilot works visually in the morning or evening during driving, train driving or flying, and the vision produced when a pilot visually operates in the night navigation with a low-light night vision device is intermediate vision. When a driver or pilot suddenly enters a darker environment in the morning or evening, a driver uses a car night vision system or a night navigation pilot uses a low-light night vision device and needs to switch to a naked vision state, the human eye needs an adaptation process (i.e. intermediate vision dark adaptation) to the rapid change of the luminance environment, which is an important factor affecting the visual operation performance.

[0004] Since the human eye in the intermediate vision state, the cone cells and rod cells both play a role in observation, but the functions of the two types of cells are not in an ideal state, and when the environmental luminance rapidly decreases (such as driving into a tunnel, removing a low-light night vision device, etc.), the human eye generally cannot quickly adapt to such changes, and various accidents caused by observation limitations are easily triggered. Therefore, the evaluation of dark adaptation ability should fully consider the intermediate vision dark adaptation function, and by investigating the physiological limitations of the human eye in the intermediate vision luminance environment, the differences in visual physiology between people can be more comprehensively and accurately evaluated, and objective and scientific basis can be provided for selecting personnel with better visual function (for example, pilots, research shows that 80% of the spatial orientation information acquisition in the flight process of pilots relies on vision).

[0005] In the past, the evaluation of the visual function of the human eye mainly used dark adaptation inspection methods, including the classic dark adaptation threshold inspection (i.e. 5 minutes of bright adaptation and 30 minutes of dark adaptation test) and the shorter time-consuming rapid dark adaptation inspection method (i.e. 2 minutes of bright adaptation and 1 minute of dark adaptation test). These methods focus on the transition of the human eye from the bright vision state (≥100 lx is the bright field, 1 lx = 1 cd / m 2The ability of rapid conversion to contrast resolution in scotopic state and the ability of adaptation of retinal photoreceptor cells to corresponding low light intensity environment are important references for medical selection or clinical ophthalmic evaluation of retinal and optic nerve functions. In recent years, although the serious driving and flight safety accidents caused by mesopic vision have been widely concerned, and the evaluation of dark adaptation function in mesopic vision has become more urgent and important. However, due to the fact that the environmental light intensity causing mesopic vision is too wide, and the environmental simulation parameters with clear application significance have not been defined (for example, which brightness caused by mesopic vision problem is representative needs to be considered), the evaluation of mesopic dark adaptation function has not been effectively carried out.

[0006] Currently, the dark adaptation examination device commonly used in clinical practice is the French My Vision Check visual function examination instrument. The examination instrument is based on the fact that the turning point of the two parts of the dark adaptation curve is at 6-8 min, and the dark adaptation response of rod cells is after the turning point. Therefore, 15 minutes after dark adaptation is set as the end point of dark adaptation function examination. However, the dark adaptation target of the examination instrument is a pure white light spot target, and the examination process is easily affected by retinal visual afterimage, resulting in that the examination of some patients who complain of night vision loss is still normal in clinical practice. In Chinese patent CN113208555A, the correct recognition time of the subject to the dark target (displayed with a brightness adjusted to 10 -3 、10 -4 cd / m 2 ) is obtained through the photopic vision adaptation stage (four warm white LED scattering lamp beads are turned on), the scotopic vision adaptation stage (four warm white LED scattering lamp beads are turned off and a blue-green dark target is displayed), and the dark adaptation test stage, so as to evaluate the dark adaptation ability of rod cells closely related to night vision function. However, the patent is for the examination of photopic vision dark adaptation function, and cannot cover the examination of dark adaptation function of human eyes in mesopic vision state, and the obtained examination results are not suitable for evaluating mesopic dark adaptation function. SUMMARY

[0007] The purpose of the present application is to provide a rapid mesopic dark adaptation function examination method, which simulates the environmental light according to the parameters such as brightness with representative application and causing mesopic vision, and considers the physiological factors such as the sensitivity of human eye retina to different light sources to design the device structure and operation, so as to realize the standardized examination and effective evaluation of mesopic dark adaptation function of human eyes in ophthalmic medical selection and identification.

[0008] In order to achieve the above purpose, the technical scheme of the present application is as follows:

[0009] In a first aspect, an intermediate vision dark adaptation function testing device is provided, which comprises an intermediate vision visual field assembly and a dark visual target assembly; the intermediate vision visual field assembly comprises an intermediate vision visual field shell and a light source arranged in the intermediate vision visual field shell for the subject to form intermediate vision; the dark visual target assembly comprises a visual target box connected with the intermediate vision visual field shell, and a luminance switching module and a visual target module arranged in the visual target box; the visual target module comprises a dark visual target display area opposite to a dark visual target observation hole arranged on the visual target box, and the luminance switching module comprises a filter for reducing the luminance of the dark visual target and a motor for driving the filter to horizontally slide between the dark visual target observation hole and the dark visual target display area.

[0010] Preferably, the light source comprises a plurality of modulable light-emitting modules for generating simulated ambient light in the intermediate vision visual field shell.

[0011] Preferably, the parameters of the simulated ambient light are: luminance ≤ 17 cd / m 2 , wavelength 540-550 nm.

[0012] Preferably, one end of the intermediate vision visual field shell is provided with an observation window, the other end of the intermediate vision visual field shell is connected with the visual target box, the dark visual target observation hole is located on the side of the visual target box opposite to the observation window, and a reflective coating is arranged on the side of the observation window and the inner surface of the intermediate vision visual field shell.

[0013] Preferably, a corrective lens insert is arranged in the observation window.

[0014] Preferably, an eyeshade connected with the intermediate vision visual field shell is arranged outside the observation window.

[0015] Preferably, the luminance switching module further comprises a motor mounting bracket, parallel threaded rods and guide rails arranged on the motor mounting bracket, and a moving block matched with the guide rails and the threaded rods, respectively, the threaded rods are connected with the main shaft of the motor, a moving light stand is arranged on the moving block, a light-shielding plate (the color of the light-shielding plate is the same as that of the reflective coating) is arranged on one side of the moving light stand in the horizontal direction, and the filter is arranged on the other side of the moving light stand.

[0016] Preferably, the luminance of the dark visual target is > 10 -3 cd / m 2 , and the luminance of the dark visual target after passing through the filter is reduced to < 10 -3 cd / m 2 .

[0017] Preferably, the dark visual target assembly further comprises a camera for monitoring the eyes of the subject, and the camera is arranged in the visual target box.

[0018] Preferably, the examination device further comprises a headgear connected to the mesopic field of view housing.

[0019] Preferably, the examination device further comprises a main unit connected to the mesopic field of view assembly and / or the scotopic symbol assembly.

[0020] In a second aspect, a method for examining mesopic dark adaptation function is provided, the method comprising the following steps:

[0021] (1) Mesopic adaptation stage

[0022] The subject is allowed to form mesopic vision by using the mesopic field of view and maintain for a certain period of time (e.g. 120 seconds);

[0023] (2) Dark adaptation stage

[0024] The mesopic field of view is turned off and a scotopic symbol with an initial display brightness is provided for the subject to recognize;

[0025] (3) Test stage

[0026] The time for the subject to recognize the scotopic symbol after the brightness of the scotopic symbol is reduced is recorded.

[0027] Preferably, the mesopic field of view is generated by simulated ambient light with a brightness of ≤ 17 cd / m 2 , wavelength 540-550 nm.

[0028] Preferably, in step 2, the initial display brightness is > 10 -3 cd / m 2 .

[0029] Preferably, in step 3, the brightness of the scotopic symbol is reduced to < 10 -3 cd / m 2 .

[0030] The beneficial effects of the present application are embodied in:

[0031] In the present application, the brightness of the scotopic symbol is reduced by using a horizontally slidable filter driven by a motor, avoiding repeated reduction of the brightness of the scotopic symbol in the test stage, and the dark adaptation time after stimulation of the mesopic field of view can be accurately obtained, thereby realizing effective evaluation of the mesopic dark adaptation function.

[0032] Further, by providing a light shielding plate and a filter separated therefrom, the need for recognizing the scotopic symbol in the examination is met, and the accuracy of the examination results is improved.

[0033] Further, by scientifically setting representative parameters (maximum brightness 17 cd / m 2, wavelength 540-550 nm), providing a new way for visual function examination (especially for intermediate vision related examination). BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 The schematic diagram of the overall structure of the intermediate vision dark adaptation function examination terminal is shown in the figure.

[0035] Figure 2 The schematic diagram of the assembly of the intermediate vision dark adaptation function examination terminal is shown in the figure.

[0036] Figure 3 The schematic diagram of the intermediate vision field of view assembly is shown in the figure. Figure 2 The schematic diagram of the intermediate vision field of view assembly is shown in the figure.

[0037] Figure 4 The schematic diagram of the target module of the scotopic target assembly is shown in the figure. Figure 2 The schematic diagram of the brightness switching module of the scotopic target assembly is shown in the figure.

[0038] Figure 5 The schematic diagram of the target module of the scotopic target assembly is shown in the figure. Figure 2 The schematic diagram of the target module of the scotopic target assembly is shown in the figure.

[0039] Figure 6 The frequency distribution of the intermediate vision dark adaptation examination results of 100 subjects is shown in the figure: mean = 67.86, standard deviation = 39.855.

[0040] In the figure: 1-headgear, 2-light shielding eyecup, 3-intermediate vision field of view assembly, 4-scotopic target assembly, 5-front cover; 30-intermediate vision field of view shell, 31-light source plane, 32-corrective lens insert, 33-LED lamp; 40-target box, 41-camera, 42-connector, 43-brightness switching module, 44-target module; 430-absorbing neutral density filter, 431-stepper motor mounting rack, 432-stepper motor, 433-moving light stand, 434-moving block, 435-rail, 436-light shielding whiteboard; 440-driving board, 441-display screen, 442-light reduction filter, 443-narrowband filter, 444-mounting plate, 445-mounting plate through hole. DETAILED DESCRIPTION

[0041] The application will be further described in detail below in combination with the drawings and examples. The examples are only used to explain the application, and are not a limitation on the protection scope of the application.

[0042] (I) Structure design of intermediate vision dark adaptation function examination terminal

[0043] As Figure 1 and Figure 2As shown, the intermediate visual dark adaptation function inspection terminal mainly consists of a sponge-made light-blocking eyecup 2, an intermediate visual field assembly 3, a dark visual mark assembly 4, a front cover 5 and a headgear 1. The headgear 1 includes a horizontal plane band and a sagittal plane band, the two ends of the horizontal plane band are respectively bound by the fixed buckles located on the left and right sides of the intermediate visual field assembly 3, the main body of the sagittal plane band is located on the upper side of the horizontal plane band, and one end of the sagittal plane band is bound by the fixed buckle located on the top of the side (i.e. the front side of the intermediate visual field assembly 3) where the intermediate visual field assembly 3 and the dark visual mark assembly 4 are connected, and the other end of the sagittal plane band is fastened with the middle part of the horizontal plane band by means of pasting or sewing, etc., so that after the subject wears the intermediate visual dark adaptation function inspection terminal through the headgear 1, the subject's eyes can be made to face the observation window located on the rear side of the intermediate visual field assembly 3, wherein the horizontal plane band and the sagittal plane band are pasted by means of self-adhesion or magic tape, etc., which can quickly adjust the tightness of the intermediate visual dark adaptation function inspection terminal worn on the head after being connected with the corresponding fixed buckles, and make the sponge-made light-blocking eyecup 2 connected outside the observation window tightly adhere to the subject's eyes (specifically the lateral side of the eye socket). The front side of the dark visual mark assembly 4 faces the observation window, so as to display the dark visual mark for the subject to identify at a certain depth of field of the subject's eyes. The front cover 5 is installed on the rear side of the dark visual mark assembly 4 (opposite to the side where the dark visual mark provided by the dark visual mark assembly 4 can be observed), so that the dark visual mark assembly 4 is easy to maintain.

[0044] As shown, Figure 2 The dark visual mark assembly 4 specifically includes a mark box 40 (opaque), a brightness switching module 43, a mark module 44, a camera 41 and a connector 42. The mark module 44 and the camera 41 (the latter with a mounting socket) are respectively installed on the side of the mark box 40 opposite to the intermediate visual field assembly 3 and away from the front cover 5, the brightness switching module 43 is installed at the bottom of the mark box 40, the host interface of the connector 42 is fixed on the mark box 40, and the lead terminals of the connector 42 are connected with the driving circuit integrated in the mark module 44 through a cable (not shown). Figure 2 The side of the mark box 40 opposite to the intermediate visual field assembly 3 and away from the front cover 5 is closed, and only a dark visual mark observation hole is opened on the position opposite to the observation window and an eye movement (specifically the subject's blinking or closing eyes) monitoring hole is opened on the position opposite to the camera 41 on the closed side, and the mark box 40 has mounting holes on the top, the bottom and the four corners of the closed side for engaging and fixing with the intermediate visual field assembly 3 (the open side of the mark box 40 is used for embedding and installing the front cover 5).

[0045] As shown, Figure 3As shown, the intermediate vision field assembly 3 specifically comprises an intermediate vision field housing 30 (with the observation window and securing buckle), a corrective lens insert 32, and an intermediate vision field light source. The intermediate vision field housing 30 is made of polymer materials using additive printing technology, resulting in an ergonomic design that allows the observation window to fit the eyes of most subjects before the examination begins. The corrective lens insert 32 is installed within the observation window, facilitating the placement of spectacle lenses (e.g., optical corrective lenses, which prevent subjects from seeing dark sight marks due to myopia or hyperopia, thus helping to eliminate errors in the examination results). A finishing layer is formed by spraying barium sulfate throughout the interior of the intermediate vision field housing 30 to enhance the reflective uniformity of the intermediate vision field light source (giving the inner surface of the intermediate vision field housing 30 a white appearance; the sight mark box 40, facing the intermediate vision field assembly 3 and away from the front cover 5, is also sprayed with barium sulfate). The exterior of the intermediate vision field housing 30 (i.e., the outer surface where the fixing buckle is located) is sprayed with a matte black polyurethane enamel to prevent the impact of external light reflections on the inspection. The intermediate vision field light source primarily comprises four modulated (brightness, spectral peak) light modules (e.g., LEDs 33) mounted at the four corners of a plane (referred to as the light source plane 31) within the intermediate vision field housing 30, located further forward than the observation window (i.e., farther from the subject's eyes). During the inspection, the light source within the intermediate vision field housing 30 can be used to simulate ambient light conditions that induce intermediate vision in the subject. After the subject's eyes remain in the intermediate vision state induced by the simulated ambient light for a certain period of time, the host computer can shut off the intermediate vision field light source and utilize the relevant modules of the dark-vision target assembly 4 to complete the inspection of the subject's dark adaptation function.

[0046] like Figure 4 As shown, the brightness switching module 43 specifically includes a movable optical frame 433, an absorptive neutral density filter 430, a stepper motor mounting frame 431, a guide rail 435, a moving block 434, and a stepper motor 432. The stepper motor mounting frame 431 is fixed in the sight mark box 40, and the stepper motor 432 is fixed to one side of the stepper motor mounting frame 431. The guide rail 435 is fixed to the stepper motor mounting frame 431, and a threaded rod ( Figure 4The screw rod is connected with the spindle of the stepping motor 432. The moving block 434 is assembled on the slide rail 435 and the screw rod, wherein the slide rail 435 is relatively slidable with the moving block 434, and the screw rod is matched with the threaded hole penetrating through the moving block 434. The moving light frame 433 is fixed on the top of the moving block 434, and the upper part of the moving light frame 433 is provided with three plate holes which are same in shape and size (or similar) and arranged in a "one" shape. The middle one of the plate holes is in an idle state (without any influence on the light passing through, for example, without changing the brightness level of the dark visual target), the other plate hole on the side away from the fixed position of the stepping motor 432 is provided with the light shielding white plate 436, and the absorbing neutral density filter 430 is installed in the third plate hole closest to the fixed position of the stepping motor 432. In the examination, the moving block 434 moves linearly in stages and in sequence with the operation of the stepping motor 432 (for example, through two start-stop operations), and the middle idle plate hole and the absorbing neutral density filter 430 on the rear side of the plate hole are replaced by the light shielding white plate 436 on the front side of the plate hole in sequence to stay in the position opposite to the dark visual target observation hole through the moving light frame 433 (when the light shielding white plate 436 is in the position, the subject will directly look at the white color in the visual field in the middle vision, avoiding the determination of the accurate position of the dark visual target, and improving the accuracy of the examination results; when the absorbing neutral density filter 430 is in the position, the brightness level of the dark visual target can be reduced).

[0047] The above-mentioned stepping motor 432 can adopt a two-phase winding integrated stepping motor (1.8° step angle, static torque 0.5 kg·cm), and the working voltage is 10-30 V DC, and the rated current is 1 A. The above-mentioned absorbing neutral density filter 430 can select corresponding filters with different optical densities (that is, different attenuation coefficients), so as to change the transmittance of the corresponding light emitted by the component for generating the dark visual target in the visual target module 44, and realize the switching to the dark visual target with lower brightness level, such as 10 -4 cd / m 2 and the like.

[0048] For example, the above-mentioned absorbing neutral density filter 430 can be replaced by a light shielding white plate, and the light shielding white plate is installed in the third plate hole closest to the fixed position of the stepping motor 432. Figure 5As shown, the target module 44 specifically includes a display screen 441, a driving board 440, a light reduction sheet 442, a narrow-band filter 443, and a mounting plate 444. The display screen 441 is mounted on the front of the driving board 440 and connected to an integrated driving circuit on the back of the driving board 440 (the control unit of the camera 41 and the stepping motor 432 is connected to the integrated driving circuit through a cable), and the light reduction sheet 442 and the narrow-band filter 443 are sequentially stacked on the display screen 441 from inside to outside. The driving board 440 is fixed to the target box 40 through the mounting plate 444, and a gap is left between the driving board 440 and the mounting plate 444 to facilitate the movement of the upper part of the moving light frame 433 (i.e., the part mounting the absorbing neutral density filter 430 and the light-shielding white plate 436) between the driving board 440 and the mounting plate 444 (specifically, in front of the display screen 441), which is conducive to the miniaturization and compactness of the dark target assembly 4. In order to avoid the mounting plate 444 blocking the dark target observation hole (causing the subject to be unable to identify the dark target through binocular observation), a mounting plate through hole 445 is provided on the mounting plate 444 (the mounting plate through hole 445 is opposite to the dark target observation hole and the narrow-band filter 443 on both sides of the mounting plate through hole 445, and the area of the mounting plate through hole 445 should be no less than the area of the dark target observation hole, so as to avoid the subject finding the possible position of the dark target observation hole as much as possible when the mesopic vision field light source is working, thereby ensuring the actual effect of the examination).

[0049] The display screen 441 adopts a 0.77-inch micro high-resolution AMOLED screen, with a resolution of 1280x1024, a pixel point distance of 12 µm, a display area of 15.36 mmx12.29 mm, RGB vertical strip pixel arrangement, 8 bits / 256 gray levels, brightness≥150 cd / m 2 , uniformity>85%, with the characteristics of self-luminous, wide viewing angle, and low power consumption; the narrow-band filter 443 adopts a narrow-band filter with a center wavelength of 512 nm, a half-bandwidth of 25 nm, a size of 17.5 mmx17.5 mm, a thickness of 1.1 mm, and a peak pass rate of 60%-70%; after the light reduction sheet 442 and the narrow-band filter 443, a blue-green dark target with a brightness level lower than that of the AMOLED screen itself (for example, a brightness of 10 -2 cd / m 2 ) can be formed in the display area for the subject to identify.

[0050] (II) Use and parameter optimization of mesopic dark adaptation function examination terminal

[0051] ① Examination process of mesopic dark adaptation function examination terminal

[0052] Mainly includes the intermediate visual adaptation stage (intermediate visual field light source, display screen 441 are opened in turn, the latter display area formed by the dark visual mark is blocked by the light shielding white board 436 to observe), dark adaptation stage (only display screen 441 is opened, the dark visual mark formed by its display area is observed by the subject through the two eyes), test stage (only display screen 441 is opened, the dark visual mark formed by its display area is reduced in brightness by the absorbing neutral density filter 430, and the time when the subject observes and identifies the dark visual mark, i.e. the examination time, is recorded).

[0053] Wherein, in the intermediate visual adaptation stage, the eye image of the subject collected by the host using the camera 41 is used to automatically analyze the open / closed eyes of the subject, and the subject is reminded to open the eyes through voice output, so as to reduce the false negative caused by the conscious or unconscious closing of the eyes of the subject in the intermediate visual adaptation process (prevent the human eye from entering the dark adaptation process in advance, resulting in the shortening of the examination time obtained in the test stage and the improvement of the evaluation result).

[0054] ②Any one of the four direction arrows "↑", "→", "↓" and "←" is used as the shape of the dark visual mark (displayed synchronously by the host), and the arrow direction is randomly switched from the current direction to other directions as the brightness of the dark visual mark decreases, thereby reducing the false negative of the dark visual mark-based examination.

[0055] ③Since the focus of the examination is the dark adaptation ability of the cone cells and rod cells mixed action (and mainly rod cells), and experiments show that, when the intermediate visual field light source is turned off, 10 -2 cd / m 2 , 10 -4 cd / m 2 (the latter is the reduced brightness, only stimulating the rod cells, not stimulating the cone cells) as the brightness parameter of the dark visual mark can ensure the accuracy of the examination of the function of the rod cells. Therefore, the brightness lower than 10 -3 cd / m 2 , such as 10 -4 cd / m 2 , is used as the brightness of the dark visual mark for testing.

[0056] ④ The human eye in 10 -3 cd / m 2 to 10 2 cd / m 2The brightness range is the intermediate vision state, at this time, both cones and rods work, and it is necessary to determine the time (the shorter the time, the better) that the human eye can recognize (i.e. see clearly) the target after the ambient brightness suddenly drops to an extremely low level (much lower than the ambient brightness of the dark vision target used in the examination) in this state. Representative parameters need to be selected. At the same time, visual physiology is combined, namely the Parkinson shift phenomenon that exists in the human eye when the ambient brightness drops, the color gamut change of rod cells in the low brightness environment (rod cells tend to respond to stimuli with shorter wavelengths), and the different spectral responses of cones and rods. Finally, experiments have proved that it is better to select a brightness environment that is higher in the working threshold of rod cells (for example, a brightness of 17 cd / m 2 , green light with a wavelength of 540-550 nm) for intermediate vision adaptation, which not only scientifically simulates the ambient light that forms intermediate vision, but is also more meaningful for understanding the function of rod cells and has universal representativeness.

[0057] (3) Verification of the effectiveness of dark adaptation function test of mesopic vision

[0058] Instruments are used to evaluate the dark adaptation function of intermediate vision in healthy people with normal visual function, and normal reference values ​​are calculated to provide a scientific basis for the selection and identification of the dark adaptation ability of intermediate vision of the human eye under the mixed action of cones and rods in ophthalmology.

[0059] 3.1 Overview of the Experimental Process

[0060] One hundred healthy individuals (78 males and 22 females) aged 25.8 ± 5.1 years (range, 20-43 years) were randomly selected for dark adaptation testing to green light stimulation. All subjects underwent slit-lamp microscopy and direct ophthalmoscopy to exclude organic ophthalmic disease. This study was approved by the Ethics Committee of Xijing Hospital, Air Force Medical University. All participants were informed of all experimental procedures and signed informed consent before the start of the experiment.

[0061] According to the inspection process of the terminal of the middle vision dark adaptation function, the brightness of 17 cd / m 2 and green light with a wavelength of 540-550 nm for intermediate vision adaptation (adaptation for 120 seconds), using 10 -4 cd / m 2 The brightness of the target is used as the brightness of the dark target in the test phase.

[0062] All data were analyzed using SPSS 23.0 software. The data were expressed as mean ± standard deviation, and P < 0.05 was considered statistically significant.

[0063] 3.2 Experimental Results and Conclusions

[0064] The average time of intermediate vision (green light) dark adaptation among 100 subjects was 67.9 ± 39.9 s. The number of people with a dark adaptation time of 20-40 s was the largest, accounting for 26% (Table 1). The Shapiro-Wilk test showed that the data of intermediate vision (green light) dark adaptation time did not obey normal distribution (P = 0.000), and the frequency distribution is shown in Figure 6 The reference value of intermediate vision (green light) dark adaptation time was calculated to be no more than 157.7 s (P0-P95).

[0065] Table 1. Intermediate vision (green light) dark adaptation test results of 100 subjects

[0066]

[0067] Note: The marked "*" in the numerical range indicates that the marked value is not included.

[0068] According to the above results, in the intermediate vision dark adaptation function test, the luminance of 17 cd / m 2 2 and the wavelength of 540-550 nm as the simulated environment light for forming intermediate vision can provide necessary means and clear standards for the selection and identification of pilots using low-light night vision devices, and also provide necessary means and clear standards for evaluating the dark adaptation ability of automobile and truck drivers in the twilight or dawn state, and provide necessary means and clear standards for evaluating the driving ability of automobile drivers using night vision systems.

Claims

1. A device for testing dark adaptation function of mesopic vision, characterized by: The inspection device comprises an intermediate visual field assembly (3) and a dark sight mark assembly (4); the intermediate visual field assembly (3) comprises an intermediate visual field housing (30) and a light source for forming intermediate vision arranged in the intermediate visual field housing (30); the dark sight mark assembly (4) comprises a sight mark box (40) and a brightness switching module (43) and a sight mark module (44) arranged in the sight mark box (40); the sight mark module (44) comprises a dark sight mark display area, the dark sight mark display area being opposite to a dark sight mark observation hole arranged on the sight mark box (40); the brightness switching module (43) comprises a filter for reducing the brightness of the dark sight mark and a motor for driving the filter to slide horizontally between the dark sight mark observation hole and the dark sight mark display area; The light source comprises a plurality of modulatable light emitting modules for generating simulated ambient light in the intermediate visual field housing (30); The parameter of the simulated ambient light is brightness>10 -3 cd / m 2 and ≤17 cd / m 2 , wavelength 540~550 nm.

2. The device for testing dark adaptation function of mesopic vision according to claim 1, characterized in that: One end of the intermediate visual field housing (30) is provided with an observation window, and the other end is connected to the sight mark box (40), the dark sight mark observation hole is located on the side of the sight mark box (40) opposite to the observation window, and a reflective coating is provided on the side of the side facing the observation window and on the inner surface of the intermediate visual field housing (30).

3. The device for testing dark adaptation function of mesopic vision according to claim 1, characterized in that: The brightness switching module (43) further comprises a motor mounting frame, a parallel threaded rod and a guide rail (435) arranged on the motor mounting frame, and a moving block (434) cooperating with the guide rail (435) and the threaded rod, wherein the threaded rod is connected to the main shaft of the motor, and a moving light frame (433) is arranged on the moving block (434), and a light shielding plate is arranged on one side of the moving light frame (433) in a horizontal direction on the moving light frame (433), and the filter is arranged on the other side of the moving light frame (433).

4. The device for testing dark adaptation function of mesopic vision according to claim 1, characterized in that: The brightness of the dark target is>10 -3 cd / m 2 After passing through the filter, the brightness of the dark target is reduced to <10 -3 cd / m 2 .

5. The device for testing dark adaptation function of mesopic vision according to claim 1, characterized in that: The dark sight mark assembly (4) further comprises a camera (41) for monitoring the eyes of the subject, and the camera (41) is arranged in the sight mark box (40).

6. The device for testing dark adaptation function of mesopic vision according to claim 1, characterized in that: The inspection device further comprises a headband (1) connected to the intermediate visual field housing (30).

7. A method for testing the dark adaptation function of mesopic vision using the device for testing the dark adaptation function of mesopic vision according to any one of claims 1 to 6, characterized in that: The following steps are involved: Intermediate visual adaptation stage The intermediate visual field is used to enable the subjects to form intermediate vision and maintain it for a certain period of time; Dark adaptation stage The intermediate visual field was closed, and then a dark visual mark with an initial display brightness was provided for the subjects to identify; Testing phase After reducing the brightness of the dark visual mark, record the time it takes the subject to identify the dark visual mark; The intermediate visual field is brighter than 10 -3 cd / m 2 and ≤17 cd / m 2 , simulated ambient light with a wavelength of 540 to 550 nm is generated.

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