Vision testing system and procedures for checking the eyes

Abstract

Vision testing system (10, 42) for checking the eyes of a test subject, comprising a display device (11, 12, 13, 45, 46) with which vision test symbols can be visualized for at least one eye of the test subject (44), comprising a control unit (14) for controlling the display device, wherein the display device comprises a backlit screen (19, 30, 35), wherein the screen has an adjustment device for adapting a screen luminance to an ambient luminance, wherein the adjustment device has a measuring device for measuring the screen luminance, characterized in that the vision testing system (10, 42) comprises as a display device a stationary distance test display device (11, 12, 45) whose display area size is designed for vision tests with a viewing distance of 3 m to 10 m, and as a display device a portable near test display device (13, 46),the display area of ​​which is designed for vision tests with a viewing distance of 10 cm to 3 m, wherein the remote test display device has a camera device (25) by means of which the eyes of the test subject (44) can be recorded.

Description

[0001] The invention relates to a vision testing system and a method for checking the eyes of a test subject, comprising a display device with which vision test symbols can be visualized for at least one eye of the test subject, comprising a control unit for controlling the display device, wherein the display device comprises a backlit screen, wherein the screen has an adjustment device for adjusting a screen luminance of the screen to an ambient luminance, wherein the adjustment device has a measuring device for measuring the screen luminance.

[0002] Such vision testing systems are well-known and regularly used to conduct vision tests. While a subject's refractive values ​​can be objectively determined using an aberrometer, the refractive values ​​subjectively perceived as optimal by the subject may differ from the objectively determined refractive values. A discrepancy between objective and subjective refractive values ​​is observed, among other things, when subjective refractive values ​​are determined under mesopic or scotopic lighting conditions. In particular, the refractive values ​​determined objectively under twilight or night vision may differ from the refractive values ​​determined subjectively under the same lighting conditions.

[0003] To create these lighting conditions for an eye test, the test subject is presented with optotypes on a backlit screen, while simultaneously the screen luminance and ambient luminance are reduced. The room in which the eye test is conducted is darkened, and the background of the optotypes on the screen is also darkened to simulate the desired visual conditions of twilight or night vision. Furthermore, the display devices or screens have a control unit that allows an operator to control the display of optotypes on the screen. This control unit can, for example, be designed like a remote control. Depending on the type of screen, it may have linear or circular polarization.The screen's polarization is regularly used for vision tests in conjunction with a trial frame or phoropter. The camera device can be used, for example, to measure the eyes, although measurements are hardly possible in simulated twilight or night vision due to the lighting conditions.

[0004] Screens that can adjust their screen luminance or backlight luminance depending on the ambient luminance are already known. For example, some mobile phones have this function. In these known screens, an optoelectronic sensor measures the light incident on the sensor or the ambient luminance, and the screen luminance is controlled or adjusted accordingly via the screen's backlight. For example, if the ambient luminance increases, the screen luminance also increases, and vice versa. However, such adjustment devices have the disadvantage that the discrete electronic components of the adjustment device, such as the optoelectronic sensor, regularly exhibit a non-linear response curve.The adjustment of screen luminance to ambient luminance is therefore not proportional, but rather follows a function determined by the functions of the respective electronic components of the adjustment device. This non-linear function of the screen luminance adjustment to ambient luminance thus distorts the results of subjective refraction measurements under changing, varying lighting conditions.

[0005] A vision testing system comprising at least one LCD monitor for displaying optotypes is known from US patent 2012 / 0075586 A1. In particular, a calibration sensor is provided, which is positioned in front of the monitor and measures, among other things, the monitor's brightness or luminance as well as the ambient lighting. This sensor can be used to control these parameters on the monitor. Furthermore, a video camera is provided, which can be used, for example, to record a test subject's eye movements.

[0006] WO 2014 / 064719 A1 discloses a vision testing system that can comprise several display devices of varying sizes. These display devices can be designed like a tablet computer and connected to a control unit, through which a subject can be presented with various vision tests. Furthermore, the display devices can have an integrated camera for recording the subject's eyes.

[0007] WO 2012 / 106236 A2 discloses a vision testing system with an LCD monitor combined with a further device for presenting light stimuli. A camera is also integrated into this device.

[0008] Another LCD monitor for displaying optotypes is covered by DE 10 2014 223 442 A1, which provides for displaying the optotypes within a three-dimensional image. A tablet computer is used to control the monitor or display device.

[0009] A tablet computer for conducting various vision tests is known from US patent 2013 / 0141697 A1. Among other things, the tablet computer's camera is used to take a photograph of a test subject.

[0010] A display device of a vision testing device is disclosed in WO 2015 / 028722 A1, wherein the vision testing device may have ambient light sensors by means of which a luminance of the display device can be controlled.

[0011] The present invention therefore aims to propose a vision testing system and a method for checking the eyes of a subject using a vision testing system, which makes it possible to obtain more accurate results in vision tests.

[0012] This problem is solved by a vision testing system having the features of claim 1 and a method having the features of claim 11.

[0013] The vision testing system according to the invention for checking the eyes of a test subject comprises a display device with which vision test symbols can be visualized for at least one eye of the test subject, and a control unit for controlling the display device, wherein the display device comprises a backlit screen, wherein the screen has an adjustment device for adjusting the screen luminance to an ambient luminance, wherein the adjustment device has a measuring device for measuring the screen luminance, wherein the vision testing system comprises, as a display device, a stationary distance test display device whose display area size is designed for vision tests with a viewing distance of 3 m to 10 m, and as a display device, a portable near test display device whose display area size is designed for vision tests with a viewing distance of 10 cm to 3 m, wherein the distance test display device has a camera device.are perceptible via the subject's eyes.

[0014] In particular, the fact that the adjustment device includes a measuring device for measuring the screen luminance makes it possible to control the screen's backlight and thus its luminance. The measuring device allows for continuous monitoring of whether the measured screen luminance corresponds to a predefined screen luminance at a given ambient luminance. If the measured screen luminance deviates from the predefined screen luminance, the adjustment device can correct it accordingly, ensuring that the measured screen luminance matches the predefined screen luminance. Consequently, regardless of the characteristic curves of discrete electronic components in the display device, the adjustment device allows for proportional adjustment of the screen luminance to an ambient luminance.This is achieved according to a linear characteristic curve, which allows for even more accurate vision tests due to the consistent display conditions of vision test symbols under varying ambient luminance. In principle, the screen can also be equipped with, for example, linear or circular polarization, or another device that can be used for image separation.

[0015] In one embodiment, the measuring device can include an optoelectronic sensor that may be arranged adjacent to or in front of a display area of ​​the screen, such that the screen luminance can be measured. The optoelectronic sensor can, for example, be arranged in a longitudinal side or corner of a frame of the screen, such that light emitted from the screen falls onto the optoelectronic sensor. The optoelectronic sensor can be arranged so that it is not directly in front of the display area of ​​the screen, but merely adjacent to it. Alternatively, the optoelectronic sensor can be arranged directly in front of the display area, at a distance from the display area, or directly adjacent to it.This arrangement of the optoelectronic sensor makes it possible to measure the screen luminance relatively accurately without the optoelectronic sensor being visually disruptive in front of the display surface.

[0016] The measuring device can include an additional optoelectronic sensor for measuring ambient luminance. This additional optoelectronic sensor can also be located within the screen frame or at another point on the display device. It is essential that light emitted from the screen does not fall onto the additional optoelectronic sensor, as this could distort the measurement result. This makes it possible to measure and control both the ambient luminance and the screen luminance accordingly.

[0017] The display area of ​​the distance test display device for vision tests can be configured for a viewing distance of 4 m to 8 m, and the display area of ​​the near test display device for vision tests can be configured for a viewing distance of 30 cm to 1 m. The distance test display device can then be used to display test symbols for testing distance vision, and the near test display device can be used to display test symbols for testing near vision. The vision testing system can include either the distance test display device or the near test display device, and optionally other display devices, or both the distance test display device and the near test display device, and optionally other display devices. The distance test display device can preferably be stationary at the viewing distance specified above relative to the test subject or mounted on a wall.If the subject is positioned at a defined viewing distance relative to the distance test display for the purpose of conducting vision tests, the viewing distance to the distance test display can be precisely determined. Furthermore, the display area of ​​the distance test display can then be many times larger than that of the near test display, as comparatively larger vision test symbols may be displayed on the distance test display. Because the near test display is portable, it can be held or positioned at virtually any distance within the viewing distance specified above, relative to the subject's eyes, by an operator or the subject themselves. This allows for vision tests to be performed at a wide variety of viewing distances to the near test display.Both the remote test display unit and the near test display unit can be remotely controlled by an operator using the control unit.

[0018] The control unit can be a mobile phone or a tablet computer. These control units have a touchscreen that allows an operator to conveniently select different vision tests or visual acuity symbols and assign them to the display device. Furthermore, the control unit can be programmed to fully control the display device; that is, the display device then only serves to show the visual acuity symbols initiated by the control unit. Independently of the display device, changes to the visual acuity symbols or new vision tests can be uploaded to the control unit via a software update, without requiring an update to the display device itself. The control unit can communicate wirelessly with the display device via Wi-Fi or Bluetooth.However, the control unit can also be a permanently installed computer or a laptop on which software for controlling the display device can be run.

[0019] The near-vision display device can include a camera for recording images of the subject's eyes. This camera can be a digital camera or a camera chip with a lens, integrated into a frame of the screen. When recording the subject's eyes, the camera can capture and measure, among other things, pupillary distance, illumination-dependent pupil diameter, measuring distance, head tilt, and / or gaze direction or fixation. This information can then be used in further vision tests.

[0020] The display device can include a lighting device with an infrared light source, which can be used to illuminate the subject's eyes. Particularly when vision tests are performed under mesopic or scotopic lighting conditions, the reduced ambient light makes it difficult to photograph a subject's eyes with a camera device for specific vision tests. With the infrared light source, the subject's eyes can be illuminated with infrared light independently of ambient lighting and photographed using a suitably adapted camera device. This also advantageously avoids glare for the subject caused by illuminating the eyes with infrared light. The lighting device can also be designed to include multiple infrared light sources, such as IR LEDs. The infrared light sources can be positioned directly adjacent to a camera device.Preferably, two infrared light sources can be positioned equidistant from the camera device, in the same plane as the subject's eyes. It is also possible to position infrared light sources within the display unit. This makes it possible to determine whether the refractive values ​​objectively measured during twilight or night vision differ from subjectively measured refractive values ​​obtained under the same lighting conditions and thus with the same pupil diameter.

[0021] The camera device and / or the infrared light source can then be moved into a storage position within the display device or into a recording position outside the display device. Furthermore, the camera device and / or the infrared light source can be positioned on the screen, allowing the camera to be retracted into a storage position, for example behind the screen, or moved to a recording position next to the screen as needed. A drive unit within the camera device can move the camera from the storage position to the recording position and back. If a relatively large camera is used, a deflecting prism can be incorporated, allowing the camera to be positioned behind the screen in a space-saving manner.

[0022] Furthermore, the display device may include a glare device by means of which the subject's eyes can be illuminated. The glare device may comprise at least one light source located adjacent to the screen. For example, the light source may be a light-emitting diode (LED). The light source may be integrated into a frame of the display device. It may also be provided that a light source of the glare device is arranged on each long side of the display device's screen.

[0023] The vision testing system can include a phoropter or a trial frame. This makes it possible to determine the refraction of each subject's eyes individually. The phoropter or trial frame can also have color filters or polarization filters, each adapted to a specific color representation and / or polarization of the screen, allowing for monocular and binocular vision tests. For example, if a phoropter or trial frame with linear or circular polarization is already available, the display device of the vision testing system can be selected to be polarized to match the phoropter or trial frame. A polarization correction, such as with a λ / 4 filter, is therefore unnecessary.

[0024] Furthermore, the vision testing system can include a building automation system for lighting control, which can be operated via the control unit. This building automation system could be, for example, an electrically operated blind, a roller shutter, and / or artificial lighting in the room where the vision testing system is used. For instance, the control unit can then be used to open or close a roller shutter or to control the brightness of the interior lighting. Control of the building automation system via the control unit can be achieved, for example, via Wi-Fi or Bluetooth, allowing an operator to conveniently adjust the lighting conditions in the examination room for specific vision tests while operating the display device.Among other things, it may also be provided that when a specific vision test is selected by an operator at the control unit, the building services equipment is automatically controlled by the control unit to adjust the lighting conditions to the vision test.

[0025] In the inventive method for checking the eyes of a subject with a vision testing system, visualized vision test symbols are displayed to at least one eye of the subject by a display device of the vision testing system, wherein the display device is controlled by a control unit of the vision testing system, wherein the display device comprises a backlit screen, wherein an adjustment of the screen luminance to an ambient luminance takes place, wherein the adjustment of the screen luminance is proportional to the ambient luminance, wherein the vision testing system comprises a stationary distance test display device and a portable near test display device, wherein a pupillary distance and / or a pupil diameter measured with the distance test display device is used in a measurement with the near test display device.

[0026] In the method according to the invention, the screen luminance is adjusted to the ambient luminance by means of an adjustment device such that the ratio between screen luminance and ambient luminance is always linear. In principle, the screen can also be designed, for example, with linear or circular polarization, or with another device that can be used for image separation. For the advantages of the method according to the invention, reference is made to the description of advantages of the vision testing system according to the invention.

[0027] According to the invention, the vision testing system comprises a stationary distance test display device and a portable near test display device, wherein a pupillary distance and / or pupil diameter measured with the distance test display device is used in a measurement with the near test display device. If a subject is placed in front of the distance test display device at a defined viewing distance or measurement distance, the measurement distance is then known. The subject's pupillary distance can then be measured using a camera device of the display device. With a known measurement distance, the pupillary distance can be determined from a camera image using image processing. It is also possible to determine an illumination-dependent pupil diameter in this way. The pupillary distance and / or pupil diameter can be used in a measurement with the near test display device such that a measurement distance or...The viewing distance between a subject's eyes and the screen of the near-vision display device is calculated. If the near-vision display device also has a camera, image processing can be used to capture the subject's pupillary distance or pupil diameter from the camera image and compare it to the pupillary distance and pupil diameter measured by the distance-vision display device. This allows the measurement distance to be calculated in relation to the image captured by the near-vision display device or its camera. Such calculations can be performed, for example, using triangulation and executed by the control unit. The display of vision test symbols can then always be based on the actual measurement distance of the near-vision display device.

[0028] In one embodiment of the method, the screen luminance and color reproduction of a display area can be measured by an optoelectronic sensor and controlled by an adjustment device on the screen. Vision tests requiring a defined display of color or contrast for vision test symbols can then be performed with exceptional accuracy. The adjustment device can automatically control the screen luminance and color reproduction, allowing the screen to self-calibrate. The screen can be, for example, the screen of a tablet computer or a conventional television. Vision test symbols can be displayed with a screen backlight of 90 to 300 cd / m². 2Screen luminance can be adjusted. While it is possible to display the vision test symbols in grayscale, this is not necessary, as the screen luminance can be easily adjusted via the backlight control.

[0029] Using a camera on the display device, the interpupillary distance, pupil diameter, measuring distance, head tilt, and / or gaze direction of the subject's eyes can be captured and measured. If the subject's viewing distance to the screen is known in principle due to the fixed positioning of both the screen and the subject, the interpupillary distance can be calculated from an image of both eyes captured by the camera device or a camera using image processing. A relative distance between the pupils can be used, for example, to fit eyeglasses or to administer specific vision tests. The pupil diameter can also be measured in this way depending on the ambient lighting. Conversely, if the interpupillary distance is known, a measuring distance or viewing distance of the subject relative to the screen can be calculated from an image captured by the camera device using image processing.It is also possible to record the subject's head tilt relative to the screen as well as the direction of gaze or fixation on visual acuity test symbols.

[0030] Using a camera on the display device, the pupil diameter can be measured, allowing for a vision test to be performed on a subject under twilight or night vision conditions. Only then, by illuminating the pupils with infrared light via a lighting device, is it possible to measure the pupil diameter and determine a subjective refraction under mesopic or scotopic visual conditions. The subjective refraction values ​​can then be compared with objective refraction values ​​measured at essentially the same pupil diameter. The objective refraction values ​​can, for example, be automatically transmitted from a measuring device to the vision testing system.

[0031] It is therefore particularly advantageous if the display device's orientation sensor can measure the screen's position, especially its tilt, relative to the subject's eyes. The orientation sensor can be a gyroscopic sensor, which allows the spatial position or orientation of the screen or display surface to be determined. For example, if the subject's eyes or head are captured with a camera on the display device, the screen's tilt relative to the eyes can be easily calculated using a known interpupillary distance. The screen can then indicate that it is tilted relative to the eyes and, for example, that an eye test cannot be performed. The screen can also display information on the correct orientation of the screen relative to the subject's eyes.The test subject may then be able to position the screen relative to their eyes in the position required for a vision test.

[0032] A camera on the display device allows for continuous tracking of the subject's eyes. This enables the calculation of a fixation point on the screen. This is possible when the subject's eye direction is recorded. In this way, vision tests can be used to examine the extent to which the subject dynamically tracks monocularly or binocularly presented visual acuity targets.

[0033] When continuous eye tracking is performed for presented visual acuity tests, monocular and / or binocular visual acuity can be determined from the interplay between eye movement and test position. This so-called eye-tracking can also be used, for example, when reading text displayed on a screen.

[0034] If a viewing distance or measuring distance is known, the vision test symbols can be displayed in a size adapted to that distance. The display of these size-adjusted vision test symbols can be automated or manual via the control unit or by an operator. This ensures that the vision test symbols are always displayed in the required size and prevents errors during vision tests.

[0035] The measuring distance of a subject's eyes relative to the screen of the near-vision display device can be determined even more precisely if the pupillary distance measured with the distance-vision display device at a known measuring distance is used for distance measurement with a camera device of the near-vision display device, taking into account the convergence of the eyes. Since, with the near-vision display device, test symbols may no longer be viewed at infinity at measuring distances of 10 cm to 3 m, the subject's eyes then focus on a test symbol presented on the screen of the near-vision display device. The gaze axes of the eyes are essentially convergent in this process. This results in a reduced pupillary distance compared to a distance-vision test or when looking at infinity, which can be taken into account when calculating a measuring distance and / or conducting vision tests.

[0036] Visualizing the visual acuity symbols allows for a vision test to be performed, determining a subject's eye deviation, monocular vision, binocular vision, daytime vision, twilight vision, or night vision. Eye deviation can be determined, for example, using the Maddox or Thorington vision tests. Monocular and binocular vision can be assessed by determining the refraction of the eyes, sometimes in conjunction with a trial frame or phoropter. In addition to conducting vision tests under photopic lighting conditions, mesopic or scotopic lighting conditions can also be set to test and determine a subject's twilight and night vision. This involves, in particular, reducing the screen luminance and ambient luminance to create mesopic or scotopic viewing conditions.For example, so-called night glasses can then be fitted to the subject with dilated pupils.

[0037] The vision test symbols can be visualized in a size adapted to the objectively measured refractive values ​​of a test subject. A subjective review of these objectively measured refractive values ​​is possible, taking into account the pupil diameter. Since the objectively measured refractive values ​​may have been determined under uniform lighting conditions with, for example, a small pupil diameter using an aberrometer, the screen luminance and ambient luminance may be reduced during the subjective review to such an extent that the pupil diameter becomes comparatively larger. This may result in subjectively measured refractive values ​​that differ from the objectively measured values.A direct comparison between objectively and subjectively measured refraction values ​​becomes possible when the visual acuity symbols are visualized in a size adapted to the objectively measured refraction values ​​of the test subject. This can be achieved by transmitting or entering the objectively measured refraction values ​​into the control unit, which then automatically selects the size of the visual acuity symbols to be displayed based on the objective refraction values.

[0038] Visualizing the visual acuity symbols allows for the determination of a subject's phoria. The phoria can be identified solely by the relative displacement of at least one visual acuity symbol perceptible only to the right eye and at least one visual acuity symbol perceptible only to the left eye. Dissociated phoria can be determined using a Maddox or Thorington vision test. This can involve using light sources such as LEDs positioned outside the screen, for example, within a frame of the display device, in conjunction with a scale displayed on the screen. Alternatively, by using a trial frame or a phoropter with a polarizing filter, a phoria can be determined by relative displacement without the need for prisms, provided that the visual acuity symbols are perceptible and movable separately by the right and left eyes.

[0039] Visualizing the visual acuity symbols can be advantageous for conducting an eye test, where the symbols can be embedded in a representation of a test subject's real-world environment. This real-world environment could, for example, be a depiction of a landscape, showing a perspective view. The visual acuity symbols can then be displayed within this landscape.

[0040] Furthermore, the environmental situation can be a traffic situation in sunshine, fog, rain, twilight, or night, with or without artificial lighting. For example, a vehicle on a road can be depicted, with visual acuity markings embedded in the license plate. The image can then be enlarged or reduced to simulate a greater subjective viewing distance to the depicted environment or vehicle. This makes it easy to check, for instance, whether a test subject is still able to recognize the vehicle's license plate from a freely selectable distance. This vision test can be varied with different lighting conditions, as described above.

[0041] Vehicle lights can also be depicted, allowing color vision deficiency to be determined by varying a single hue of the lights. The vehicle lights could be, for example, taillights or brake lights, so that a single hue is varied independently. For instance, the hue could be a shade of red, allowing the perception of this hue to be bridged by two differently varied lights.

[0042] The environmental situation can also be displayed in three dimensions. For example, the screen can be a conventional television set suitable for three-dimensional display when used with polarized glasses or trial glasses with a polarization filter. However, it is also possible to display the environmental situation in two dimensions. It is particularly advantageous to use a screen capable of displaying the environmental situation and / or the vision test markings in 4K format.

[0043] Further embodiments of the method are set out in the dependent claims relating to device claim 1.

[0044] A preferred embodiment of the invention is explained in more detail below with reference to the accompanying drawings.

[0045] They show: Fig. 1 a schematic representation of an embodiment of a vision testing system; Fig. 2 a schematic representation of an arrangement of a vision testing system.

[0046] The Fig. Figure 1 shows a vision testing system 10, comprising a distance test display unit 11, another distance test display unit 12, and a near test display unit 13, as well as a control unit 14 for controlling the display units 11, 12, and 13, respectively. The vision testing system 10 further includes a roller shutter control unit 15 with a roller shutter 16 and a controllable light source 17 in a room not shown here. The roller shutter control unit 15 and the light source 17 are also controllable by the control unit 14. The display units 11, 12, and 13, as well as the roller shutter control unit 15 and the light source 17, are connected to the control unit 14 via a WLAN network 18 for data exchange. The distance test display unit 11 consists of a screen 19 with a frame 20. The screen 19 is backlit and can be linearly or circularly polarized. Light-emitting diodes 23 are integrated into the longitudinal sides 21 and 22 of the frame 20, which together form a glare shield 24.The light-emitting diodes 23 illuminate the eyes of a test subject in such a way as to produce a glare effect. The remote test display device 11 further comprises a camera device 25 and a lighting device 26 with infrared light-emitting diodes 27. The camera device 25, together with the lighting device 26, can be lowered into the frame 20 by a motor. A display area 28 of the screen 11 is comparatively larger than a display area 29 of a screen 30 of the remote test display device 12. The remote test display device 11 can therefore be used for comparatively greater measurement distances or viewing distances for vision tests than the remote test display device 12.

[0047] The near-test display device 13 also has a camera device 31 in a frame 32 and a light-emitting diode 33 that forms a glare shield 34. The display area 36 of a screen 35 of the near-test display device 13 is comparatively small compared to the display area 29 of the distance-test display device 12. Optometry symbols or vision tests, not shown here, can be selectively displayed on the respective display areas 28, 29, and 36 via the control unit 14. Furthermore, the display devices 11, 12, and 13 each have optoelectronic sensors 37 arranged in a corner 38, 39, and 40 of the frames 20, 32, and 41, respectively. The optoelectronic sensors 37 are part of a measuring device, not shown in detail here, which measures the screen luminance of the screens 19, 30, and 35, respectively, as well as the ambient luminance of a room.The ambient luminance is measured by means of an optoelectronic sensor (not shown) integrated into frames 20, 32, and 41, respectively. The screen luminance is then adjusted proportionally to the ambient luminance by means of the control unit 14 or the display unit 11, 12, or 13. The ambient luminance, in turn, can be adjusted manually or automatically via the control unit 14 by manipulating the roller shutter 16 and the light source 17.

[0048] The Fig.Figure 2 shows a vision testing system 42 in a room 43 together with a test subject 44. The vision testing system 42 comprises a distance test display unit 45 and a near test display unit 46, as well as a trial frame 47, which the test subject 44 wears. The distance test display unit 45 is fixed to a wall 48, and the near test display unit 46 is held manually by the test subject 44. Furthermore, the room 43 is equipped with a light source 49, which allows for control of the ambient luminance. Using a control unit of the vision testing system 42 (not shown here), an operator can perform a vision test with the test subject 44 by displaying vision test symbols on the distance test display unit 45, which is located at a relatively large measuring distance relative to the test subject 44. The near test display device 46 can be handled by the subject 44 himself, whereby the measuring distance between the subject 44 and the near test display device 46 is comparatively smaller.Here too, if required, visual acuity tests can be presented to the subject 44 via the control unit.

Claims

[1] Vision testing system (10, 42) for checking the eyes of a subject, comprising a display device (11, 12, 13, 45, 46) with which vision test symbols can be visualized for at least one eye of the subject (44), comprising a control unit (14) for controlling the display device, wherein the display device comprises a backlit screen (19, 30, 35), wherein the screen has an adjustment device for adjusting a screen luminance to an ambient luminance, wherein the adjustment device has a measuring device for measuring the screen luminance, characterized by, that the vision testing system (10, 42) comprises as a display device a stationary distance test display device (11, 12, 45) whose display area size is designed for vision tests with a viewing distance of 3 m to 10 m, and as a display device a mobile near test display device (13, 46) whose display area size is designed for vision tests with a viewing distance of 10 cm to 3 m, wherein the distance test display device has a camera device (25) by means of which the eyes of the subject (44) can be recorded. [2] Vision testing system according to claim 1, characterized by , that the measuring device has an optoelectronic sensor (37) which is arranged adjacent to or in front of a display area (28, 29, 36) of the screen (19, 30, 35) such that the screen luminance can be measured. [3] Vision testing system according to claim 2, characterized by that the measuring device has an additional optoelectronic sensor with which the ambient luminance can be measured. [4] Vision testing system according to any of the preceding claims, characterized by , that the display area size of the distance test display device (11, 12, 45) is designed for vision tests with a viewing distance of 4 m to 8 m, and that the display area size of the near test display device (13, 46) is designed for vision tests with a viewing distance of 30 cm to 1 m. [5] Vision testing system according to any one of the preceding claims, characterized by , that the control unit (14) is a mobile phone or a tablet computer. [6] Vision testing system according to any one of the preceding claims, characterized by , that the near test display device (13, 46) has a camera device (31) by means of which the eyes of the subject (44) can be recorded. [7] Vision testing system according to any of the preceding claims, characterized by , that the display device (11, 12, 13, 45, 46) has a lighting device (26) with an infrared light source (27) by means of which the eyes of the subject (44) can be illuminated. [8] Vision testing system according to any of the preceding claims, characterized by , that the display device (11, 12, 13, 45, 46) has a glare device (24, 34) by means of which the eyes of the subject (44) can be illuminated. [9] Vision testing system according to any of the preceding claims, characterized by , that the vision testing system (10, 42) includes a phoropter or a trial frame (47). [10] Vision testing system according to any one of the preceding claims, characterized by , that the vision testing system (10, 42) includes a building technology device (15, 17) for light control, which can be controlled with the control unit (14). [11] Method for checking the eyes of a subject using a vision testing system (10, 42), wherein a display device (11, 12, 13, 45, 46) of the vision testing system displays visualized vision test symbols to at least one eye of the subject (44), wherein the display device is controlled by a control unit (14) of the vision testing system, wherein the display device comprises a backlit screen (19, 30, 35), wherein an adjustment of a screen luminance of the screen to an ambient luminance is performed, characterized by , that the adjustment of the screen luminance is proportional to the ambient luminance, wherein the vision testing system (10, 42) comprises a stationary distance test display device (11, 12, 45) and a mobile near test display device (13, 46), wherein a pupil distance measured with the distance test display device and / or a pupil diameter is used in a measurement with the near test display device. [12] Method according to claim 11, characterized by , that the screen luminance and / or color reproduction of a display area (28, 29, 36) of the screen (19, 30, 35) is measured by means of an optoelectronic sensor (37) and controlled by means of an adjustment device of the screen. [13] Method according to claim 11 or 12, characterized by , that by means of a camera device (25, 31) of the display device (11, 12, 13, 45, 46) a pupil distance, a pupil diameter, a measuring distance, a head inclination and / or a gaze direction of the eyes of the subject (44) is recorded and measured. [14] Method according to any one of claims 11 to 13, characterized by , that a position, in particular an inclination of the screen (19, 30, 35) relative to the eyes of the subject (44) is measured by means of a position sensor of the display device (11, 12, 13, 45, 46). [15] Method according to any one of claims 11 to 14, characterized by, that continuous eye tracking of the subject's eyes (44) is carried out by means of a camera device (25, 31) of the display device (11, 12, 13, 45, 46). [16] Method according to claim 15, characterized by , that continuous eye tracking is performed for presented visual acuity test symbols, whereby a monocular and / or binocular visual performance is determined from an interaction between eye movement and visual acuity symbol position. [17] Method according to any one of claims 11 to 16, characterized by that the vision test symbols are displayed in a size adapted to the measuring distance. [18] Method according to claim 17, characterized by , that the pupillary distance measured with the remote test display device (11, 12, 45) at a known measuring distance is used for distance measurement with a camera device (31) of the near test display device (13, 46), taking into account convergence of the eyes. [19] Method according to any one of claims 11 to 18, characterized by , that a vision test is performed by visualizing the vision test symbols, whereby the vision test determines an eye misalignment, monocular vision, binocular vision, day vision, twilight vision, or night vision of a subject (44). [20] Method according to any one of claims 11 to 19, characterized by , that visual test symbols are visualized in a size adapted to objectively measured refraction values ​​of a subject (44), whereby a subjective verification of the objectively measured refraction values ​​is carried out, the verification taking into account a pupil diameter. [21] Method according to any one of claims 11 to 20, characterized by, that by visualizing the visual test symbols a subject's phoria (44) is determined, wherein the phoria is determined solely by a shift between at least one visual test symbol perceptible by the right eye alone and at least one visual test symbol perceptible by the left eye alone. [22] Method according to any one of claims 11 to 21, characterized by , that the visualization of the vision test symbols is used to perform a vision test in which the vision test symbols are embedded in a picture reproduction of a real environmental situation. [23] Method according to claim 22, characterized by that the environmental situation is a traffic situation in sunshine, fog, rain, twilight or night with or without representation of artificial lighting. [24] Method according to claim 22 or 23, characterized by , that the lights of a vehicle are depicted, whereby color vision deficiency is determined by varying a hue of the lights. [25] Method according to any one of claims 22 to 24, characterized by that the environmental situation is depicted in a three-dimensional way.

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