Eye movement measurement device with 2D display projector and retroreflective screen

Abstract

An eye movement measurement device, comprising a projection device, the projection device comprising: a micro LED display device, the micro LED display device comprising a light emitting pixel array, and an optical lens positioned in optical communication with the micro LED display device and configured to project light within a field of view of the optical lens; the apparatus further includes a retroreflective screen positioned to overlap with the field of view of the optical lens. The projection device may be positioned proximate to one or more patient eyes, and the retroreflective screen may retroreflect light in a direction of the one or more patient eyes.

Description

TECHNICAL FIELD

[0001] The present invention relates to systems and methods for eye movement measurement examinations, including video nystagmography (VNG).

[0002] BACKGROUND

[0003] Current eye movement measurement devices have many drawbacks. One issue is the mechanical mobility nature of the laser driving the eye movement motor, which can have long-term reliability issues in laser-based solutions. There is a need in the art for a solution that achieves the same functionality using only solid-state devices to effectively point light at fixed stimulation sites or move stimulation sites on a screen in both horizontal and vertical directions.

[0004] Another issue in the art is the need for a separate fixed laser in current VNG goggles solutions. Such solutions limit the ability to use retro-reflective screens, thereby increasing the light brightness necessary to perform eye movement measurement examinations. There is a need in the art for a solution that is light and compact enough to be positionable within a goggle device.

[0005] Another issue in the art is the single stimulation site limitation, which is caused by using a single movable laser beam with limited movement speed because the eye movement motor cannot be driven fast enough to produce real-time raster scan imagery. There is a need in the art for a solution that generates real-time 2D patterns in the form of video / imagery that can be produced to enable additional balance-related tests (such as optokinetic tests), which current eye movement motor-based laser site solutions cannot provide and therefore require a separate display screen.

[0006] Another issue in the art is the size and weight of the eye movement motor subassembly, as the overall weight and size of the goggle-based eye movement measurement solution is a key usability factor. Current solutions are too large and heavy to be useful. There is a need in the art for a lighter and more compact eye movement measurement solution that facilitates being placed within a goggle that is ideally sized and comfortably weighted to improve usability, particularly when compared to the case of the eye movement motor subassembly.

[0007] Another problem in the art relates to the relatively complex mechanical design of the eye movement motor subassembly and the associated difficulty in manufacturability compared to a very simple modular design that can be manufactured separately and easily integrated into an eye movement measurement goggle. Current eye movement motors are bi-axial stepper motors that are combined with a bevel gear system to drive the laser to change its pointing direction in both x and y directions. To avoid or substantially reduce the mechanical coupling of the x and y movements, the current design becomes increasingly complex involving ball bearings, high precision bevel gears, precise adjustment of the relative positioning of the two bevel gears using shims, etc. The bi-axial motor is mounted directly on the PCBA board which makes manufacturing difficult and not modular. There is a need in the art for a subassembly that can be manufactured separately from the goggle housing, independently tested for quality control and then easily integrated into a goggle eye movement measurement device.

[0008] Another problem in the art relates to the cost of the eye movement motor subassembly. As augmented reality (AR) and virtual reality (VR) goggle become an important ongoing research and development trend, self-emitting micro-displays that are improved in cost, size and display brightness are being commercialized. Therefore, a solution that utilizes such devices would be advantageous.

[0009] Another problem in the art relates to power consumption and therefore the brightness of the stimulus or video scene on the viewing surface. Since many eye movement measurement devices are designed to be driven through a USB 3.0 cable with a limited power supply, the electrical power is limited. Therefore, when the power delivered by the USB cable is converted into optical power, the optical power is also limited. Therefore, when a two-dimensional display projector is used, the brightness of the display on a screen or wall that is about 1.5 to 2 meters away is usually limited so that the patient cannot see it clearly in a room with indoor light. This is especially true when a short throw optical projector is required, like in the case of a VNG goggle that requires an angular field of view of at least ±30 degrees in the horizontal direction and ±25 degrees in the vertical direction. Therefore, a solution is needed that can utilize a retro-reflective screen that directs the light rays that hit the screen back mainly along and around their incident light path, therefore much more light energy can be directed back to the patient’s two eyes from a retro-reflective screen than in the case of a wall where the incident beam will be scattered / reflected uncontrollably from the wall, only a much smaller proportion of the light is sent back to the patient’s eyes.

[0010] Another problem in the art is related to the projection angle field of view (FOV). Current solutions optical projectors either have very large size and short throw ratio or have limited angular FOV, which is not sufficient for eye movement measurement, specifically for video nystagmography (VNG) applications, if the projector is integrated inside the eye movement measurement goggles compactly enough. There is a need in the art for eye movement measurement solutions with wide angle projection lens conventionally and typically used for wide angle imaging applications. Since for VNG stimulus projection applications, the fact is that it is not required to have extremely well controlled size of the projected stimulus spot over the entire FOV range, as long as the stimulus spot size difference can be well controlled to meet the one degree angular range requirement, and the optical magnification difference can be produced, and the optical distortion can be calibrated so that for a certain angle or stimulus spot location, the corresponding pixel or a group of merged pixels can be turned on. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1 is a perspective view of an eye movement measurement device according to an embodiment of the present application.

[0012] Figure 2 is a schematic representation of an eye movement measurement device of Figure 1

[0013] Figure 3 is a representative plot of a pixel array of a display device of a projection apparatus according to an embodiment of the present application.

[0014] Figure 4 is a perspective view of a goggle device of an eye movement measurement device of Figure 1

[0015] Figure 5 is a flowchart illustrating a method of performing an eye movement measurement examination according to an embodiment of the present application. DETAILED DESCRIPTION

[0016] The present application will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the application are shown. The application may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the application to those skilled in the art. One skilled in the art should realize that the following description is illustrative only and is not intended to be in any way limiting. Other embodiments of the present application will readily occur to those skilled in the art having the benefit of the present disclosure. Similar reference numerals in different drawings denote similar elements. The description of embodiments of the application as set forth herein is not intended to be exhaustive or to be necessarily limited to the precise embodiments described. Various

[0017] ​​While the following detailed description includes many specific details for the purposes of exemplification, one of ordinary skill in the art will appreciate that many changes and modifications of the details can be made in the detailed description file without departing from the scope of the application. Thus, the following embodiments of the application are illustrative, but not limiting of the scope of the application or function.

[0018] In the detailed description of the application, those skilled in the art will note that directional terms such as "above," "below," "upper," "lower," and other like terms are used for purposes of orientation with respect to the figures. Also, those skilled in the art will note that the description can include other terms to convey positioning, orientation, and direction without departing from the principles of the application.

[0019] Further, in the detailed description, those skilled in the art will note that quantitative limiting terms such as "substantially," "essentially," "mostly," and other terms are used generally to mean that the object, property, or characteristic referred to makes up a large portion of the subject matter. The meaning of any of these terms depends on the context in which it is used, and the meaning can be expressly modified.

[0020] As shown and described in the various figures and accompanying text, one embodiment of the application provides an eye movement measurement device that can be used to perform video nystagmography. Referring now to Figure 1 , a device 100 according to one embodiment of the application is presented. The device 100 can include a goggle apparatus 102 and a retro-reflective screen 120. The goggle apparatus 102 can be configured to be worn by a patient. The goggle apparatus 102 can include a projection apparatus 110, as shown in Figure 2 The projection apparatus 110 can operate to emit light onto the retro-reflective screen 120, which is configured to induce a biological response, such as nystagmus, in a patient observing the retro-reflective screen 120 for a vestibular assessment. In contrast to a standard screen that reflects light projected onto it with greater scattering and / or only at very small or zero angles of incidence back in the direction of projection, the unique reflective properties of the retro-reflective screen 120, i.e., reflecting light projected onto it back in the direction it was projected, results in a substantially lower necessary intensity of light emitted by the projection apparatus. This can facilitate a smaller and more lightweight display apparatus that can be positioned in a greater variety of positions. Such positions can include within the goggle apparatus 102, as shown in the present embodiment. It is contemplated and included within the scope of the present application that the display apparatus can be positioned in other locations, including but not limited to, on headwear attached to or positioned adjacent to the patient's head, on a surface adjacent to the patient's head, etc.

[0021] The projection device 110 can include a display device 112. The display device 112 can be operable to emit light in a grid configuration. In some embodiments, the display device 112 can be a micro-LED display device and include an array of light-emitting pixels. Such embodiments can facilitate display of display light to cover a two-dimensional space, i.e., the retroreflective viewing surface 122 of the retroreflective screen 120.

[0022] The display device 112 can include one or more of the following features. In some embodiments, the display device can consume three watts or less. In some embodiments, the display device can consume two watts or less. In some embodiments, the display device can consume one watt or less. In some embodiments, the display device can consume 0.5 watts or less. In some embodiments, the display device can consume 0.4 watts or less. In some embodiments, the display device can consume 0.3 watts or less. The display device 112 can be configured to emit light in the visible spectrum, i.e., light having a peak wavelength in the range of 380 nanometers (nm) to 750 nm. In some embodiments, the display device 112 can be configured to emit light that is monochromatic, i.e., having a narrow band of wavelengths. In some embodiments, the display device 112 can be configured to emit monochromatic green light having a peak wavelength in the range of 495 nm to 570 nm.

[0023] The array of pixels can be defined by a horizontal pixel count m and a vertical pixel count n, as shown in array 300 in Figure 3 In some embodiments, the horizontal pixel count can be at least 120 pixels. In some embodiments, the vertical pixel count can be at least 100 pixels. In some embodiments, the horizontal pixel count can be at least 480 pixels and the vertical pixel count can be at least 400 pixels. It is further contemplated that the horizontal pixel to vertical pixel ratio can be 6:5, and in further embodiments, any array, whether cropped or non-cropped, has such a ratio of 6:5, a horizontal pixel count of at least 120 pixels, and a vertical pixel count of at least 100 pixels.

[0024] In some embodiments, the pixel array 300 is operable such that groups of adjacent pixels can be "merged" and operated concurrently to act as a single pixel, as shown by the pixel sub-group 302. For example, where the horizontal pixel count is at least 480 pixels and the vertical pixel count is at least 400 pixels, groups of four pixels in a 2x2 array can be merged and operated concurrently as a single pixel. As another example, where the horizontal pixel count is at least 960 pixels and the vertical pixel count is at least 800 pixels, groups of sixteen pixels in a 4x4 array can be merged and operated concurrently as a single pixel. It is contemplated and included within the scope of the present application that any number of pixels in any arrangement can be merged such that the effective array of merged pixels is at least 120 horizontal merged pixels by 100 vertical merged pixels.

[0025] To minimize the weight of the power supply element 116 (e.g., a battery or power transformer or adapter) of the eyewear device 102 in terms of voltage or current regulation, the power consumption of the display device 112 should be minimized. In the present embodiment, the maximum power draw of the display device 112 is less than or equal to 15 mW. Additionally, the optical power of the light emitted by the display device 112 must be bright enough such that its reflection off the display screen 120 can be seen by the patient eye 104 at a distance d, as discussed in greater detail below. In some embodiments, the optical power of the light emitted from each pixel or each merged pixel of the pixel array can be at least 16 nW, at least 64 nW, at least 256 nW, or in a range from at least 8 nW to at least 512 nW.

[0026] Additionally, the display device 112 is operable to change or light the pixels and / or merged pixels quickly enough, whether simultaneously or sequentially, to simulate motion, thereby generating a video display. Each change of the display device 112 can be considered a frame of the video display, where the resulting frames per second (FPS) depends on how quickly the display device 112 can change the pixels / merged pixels. In some embodiments, the display device 112 can have a frame rate of at least 15 FPS. In some embodiments, the display device 112 can have a frame rate of at least 20 FPS. In some embodiments, the display device 112 can have a frame rate of at least 25 FPS. In some embodiments, the display device 112 can have a frame rate of at least 30 FPS. In some embodiments, the display device 112 can have a frame rate of at least 35 FPS. In some embodiments, the display device 112 can have a frame rate of at least 40 FPS.

[0027] The projection device 110 may further include an optical lens 114 positioned to optically communicate with the display device 112. Specifically, the optical lens 114 may be positioned within an illumination path 111 of the projection device 110 defined by the light emission direction of the display device 112. Such an emission direction may originate from an emitting lens (not shown) fabricated on top of each microLED pixel of the display device 112. Light emitted from the display device 112 may be refracted by the optical lens 114 and projected therefrom. The direction of the light projected from the optical lens 114 may be defined as the field of view 115 of the optical lens 114 / projection device 110. The retroreflector screen 120 may be positioned relative to the goggle device 102 such that it overlaps with the field of view 115. In this embodiment, the optical lens 114 defines the field of view 115 in front of the projection device 110, the field of view being characterized by a 60° horizontal angular dimension and a 50° vertical angular dimension. In another embodiment, the field of view 115 may be characterized by a horizontal angular dimension in the range of 50° to 70° and a vertical angular dimension in the range of 40° to 60°.

[0028] The goggle device 102 may further include multiple components to achieve eye imaging. These components may include an infrared light source 134, an imaging sensor 132, a dichroic reflector 138, and a bandpass filter and / or electro-optical device 136. The dichroic reflector 138 and the bandpass filter and / or electro-optical device 136 may be combined in... Figure 4 A device is shown as 136. An infrared light source 134 may be positioned to emit infrared light, i.e., light having a peak intensity in the wavelength range of 700 nm to 1,000 nm, which is incident on the patient's eye 104. Such incident light may be caused by the light emitted by the infrared light source 134 directly incident on the patient's eye 104 or indirectly incident after being reflected by a reflective structure (such as a heat mirror 138 also included in the goggle device 102).

[0029] The patient's eye 104 can reflect infrared light incident thereon. Such reflected infrared light can be received and measured by the imaging sensor 132. The imaging sensor 132 can be any imaging device operable to measure infrared light, including but not limited to charge-coupled devices and active pixel sensors, including CMOS and N-type MOS devices. The imaging sensor 132 can be positioned to receive reflected infrared light directly from the patient's eye 104 or indirectly, such as in the case where infrared light reflected from the eye, i.e., the patient's eye 104, is incident on the hot mirror 138 and is reflected thereby in the direction of the imaging sensor 132. The reflected infrared light measured by the imaging sensor 132 can be analyzed to perform an eye movement measurement of the patient's eye 104 in response to content observed by the patient's eye on the retro-reflective screen 120, i.e., a stimulus or image generated by the projection device 110 and projected onto the retro-reflective screen 120. The included eye imaging components can further include one or both of a fixed focal length lens 135 and a variable focal length lens 133 positioned at an optical intermediate between the dichroic hot mirror 138 and the image sensor 132 to focus reflected infrared light passing therethrough so that it can be more clearly measured by the image sensor 132.

[0030] The dichroic reflective and / or electro-optical device 136 can be configured to selectively permit light in a first wavelength range to pass therethrough and cause light in a second wavelength range to be reflected thereby. In the present embodiment, the dichroic reflective and / or electro-optical device 136 can be configured to electro-optically permit visible light, i.e., light having a peak intensity in the wavelength range of 380 nm to 750 nm, to pass therethrough. Thus, reflected light 106 from the retro-reflective screen 120 can pass through the dichroic reflective and / or electro-optical device 136 and be incident on and observable by the patient's eye 104. In some embodiments, the first wavelength range of light that can pass through the dichroic reflective and / or electro-optical device can be narrower than all visible light. In some embodiments, the first wavelength range can be similar to or equal to the wavelength range of light emitted by the display device 112. In some embodiments, the first wavelength range can be 495 nm to 570 nm. In some other embodiments, the first wavelength range can be electro-optically controlled to be absorbed or scattered, thereby making the light path of the first wavelength range opaque to the patient's eye. The second wavelength range can be configured to reflect light emitted by the infrared light source 134 and reflected by the patient 104, specifically infrared light reflected by the patient's eye 104. Thus, the second wavelength range can be 700 nm to 1,000 nm.

[0031] Embodiments of electro-optical device 136 can be any material or device operable to achieve the above-mentioned reflection / transmission / absorption / scattering, including but not limited to dichroic reflectors, switchable privacy smart films / glasses (including polymer dispersed liquid crystal and suspended particle embodiments), and electrochromic films / glasses. In cases where electrochromic films / glasses are used, eyewear device 102 can further include components necessary to control the state of the electrochromic films / glasses. In cases where switchable privacy smart films / glasses are used, eyewear device 102 can further include components necessary to control the state of the switchable privacy smart films / glasses.

[0032] In the present embodiment, the combination of display device 112 and optical lens 114 can cause the projected light to thereby have a projection accuracy on retro-reflective screen 120 that is within at least one of the range of -1.0° to 1.0°, the range of -0.5° to 0.5°, or the range of -0.25° to 0.25°.

[0033] Retro-reflective screen 120 can be configured to retro-reflect light projected onto it, i.e., reflect the light back in the direction of the light source. Retro-reflective screen 120 can include any retro-reflective material known in the art, including but not limited to fabrics, laminates, films, coatings, and combinations thereof. In some embodiments, retro-reflective screen 120 can include a flexible substrate having a layer of retro-reflective material applied thereon, thereby facilitating storage of retro-reflective screen 120.

[0034] Retro-reflective screen 120 can be positioned within field of view 115 at a distance d from eyewear device 102. Distance d can be in the range of 1 meter to 3 meters. In one embodiment, distance d is 2 meters. Distance d can be selected as a function of various parameters of display device 112, including but not limited to projection accuracy of light projected onto retro-reflective screen 120, angular resolution of light retro-reflected by retro-reflective screen 120, field of view of display device 112, and intensity of light emitted by display device 112.

[0035] In some embodiments, retro-reflective screen 120 can be configured such that the reflected light thereby has an angular resolution that is at least one of less than or equal to 1.0°, less than or equal to 0.5°, or less than or equal to 0.25°.

[0036] Reference is now made to Figure 4presenting additional details regarding the eyewear device 102. The eyewear device 102 can include a housing 103 configured to at least one of accommodate and permit attachment to carry components of the projection device 110 and those described above for performing eye imaging. Further, the housing 103 can be configured to substantially conform to the shape of a human head so that patients having heads of various sizes and shapes can wear the eyewear device 102. The dichroic reflective and / or electro-optical device 136 can be positioned in front of where a patient’s eyes are located when the patient wears the eyewear device 102. The image sensor and infrared light source can be positioned in the housing 103 at a location adjacent to an aperture 105 of the housing 103 through which electromagnetic radiation (EMR) can pass. One or more of the optical components mentioned above, including one or more of the optical lens 114, the variable focal length lens 133, and the fixed focal length lens 135, can be positioned in optical communication with the aperture 105 and can further be carried by an optical component housing 107 attached to the housing 103. Further, the aperture 105 can be located at a position that is not observable by the patient’s eyes so that EMR passing through the aperture 105 cannot be directly observed by the patient.

[0037] Reference is now made to Figure 5 A method 500 according to one embodiment of the application is presented. The method 500 can position a projection device proximate to one or more patient eyes in step 502. The projection device can include a micro-LED display device including an array of light-emitting pixels and an optical lens positioned in optical communication with the micro-LED display device. The method 500 can continue at step 504 by operating the micro-LED display device to emit light from the array of light-emitting pixels. The method 500 can continue at step 506 by projecting the light emitted by the micro-LED display device from the optical lens onto at least a portion of a retro-reflective screen within a field of view of the optical lens. The method 500 continues in step 508 by retro-reflecting, by the optical lens, the light projected onto the retro-reflective screen in the direction of the one or more patient eyes. The method 500 can end at step 510 by observing movement of the one or more patient eyes in response to the one or more patient eyes observing the retro-reflected light.

[0038] The light emitted by the micro-LED display device can be monochromatic green light. Operating the micro-LED display device to emit light from the light-emitting pixel array can include operating the micro-LED device to emit light from at least one of a pixel of the pixel array or a group of adjacent pixels of the pixel array such that an angular resolution of the emitted light on the retro-reflective screen is less than or equal to 0.5°. Operating the micro-LED display device to emit light from the light-emitting pixel array can include emitting light from at least one of a pixel of the pixel array or a group of adjacent pixels of the pixel array such that a projection of the emitted light has a projection accuracy on the retro-reflective screen in a range of -0.5° to 0.5°. Positioning the projection device proximate to the one or more patient eyes can include positioning eyewear containing the projection device on a head of the patient. Operating the micro-LED display device to emit light from the light-emitting pixel array can include emitting light such that a two-dimensional motion simulation is projected onto the retro-reflective screen.

[0039] As mentioned above, the projection device 110 can be positioned substantially between where the patient’s eyes are intended to be positioned. In the present embodiment, the projection device 110 can be positioned on the bridge section 109 of the housing 103, which can sit over the bridge of the patient’s nose when the patient wears the eyewear device 102. Such a location is merely illustrative, and it is contemplated and included within the scope of the present disclosure that the projection device 110 be positioned anywhere on the housing 103.

[0040] Some of the illustrative aspects of the present disclosure can be advantageous in addressing the problems described herein and other problems that can be found by those of skill in the art.

[0041] While the above description contains many specific details, these should not be construed as limiting the scope of any embodiments but merely as illustrating typical or exemplary embodiments. Numerous other ramifications and variations are possible, within the teachings of various embodiments. While the application has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes can be made and equivalents can be substituted for elements thereof without departing from the scope of the application. In addition, many modifications can be made to adapt a particular situation or material to the teachings of the application without departing from the central scope thereof. Therefore, the application is not intended to be limited to the particular embodiments disclosed as the best or only mode contemplated for carrying out this application. Rather, it is intended to cover all embodiments falling within the description of the application. Furthermore, in the drawings and the description, there have been disclosed exemplary embodiments of the application, and although specific terms can have been employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the application therefore not being so limited. Additionally, the use of the terms first, second, etc. do not denote any ordinal, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms one, an, etc. do not denote a limitation of quantity but rather denote the presence of at least one of the referenced item.

Claims

1. An eye-tracking measurement device (100), the eye-tracking measurement device comprising: Projection device (110), the projection device comprising: A microLED display device (112), the microLED display device comprising a light-emitting pixel array (300); and An optical lens (114) positioned to optically communicate with the micro-LED display device (112) and configured to project light within the field of view of the optical lens (114); and Retroreflecting screen (120), the retroreflecting screen being configured to overlap with the field of view of the optical lens (114); The projection device (110) is configured to be positioned close to one or more patient eyes; and The retroreflector (120) is configured to reflect light in the direction of one or more patient eyes.

2. The eye-tracking measurement device (100) as claimed in claim 1, wherein the micro-LED display device (112) is monochrome.

3. The eye-tracking measurement device (100) as claimed in claim 2, wherein the micro-LED device is configured to emit green light.

4. The eye-tracking measurement device (100) as claimed in claim 1, wherein light emitted from a pixel of the light-emitting pixel array (300) or at least one of a group of adjacent pixels of the light-emitting pixel array (300) and reflected back by the retroreflection screen (120) has an angular resolution of less than or equal to 0.5° on the retroreflection screen (120).

5. The eye-tracking measurement device (100) as claimed in claim 1, wherein light emitted from a pixel of the pixel array or at least one of a group of adjacent pixels of the pixel array has projection accuracy on the retroreflective screen (120) in the range of -0.5° to 0.5°.

6. The eye-tracking measurement device (100) of claim 1, wherein the pixel array has a size of at least 120 horizontal pixels by 100 vertical pixels.

7. The eye-tracking measurement device (100) as claimed in claim 1, wherein the field of view of the optical lens (114) is greater than or equal to 60° horizontally and greater than or equal to 50° vertically.

8. The eye-tracking measurement device (100) as claimed in claim 1, wherein the retroreflective screen (120) comprises at least one of retroreflective fabric, retroreflective laminate, retroreflective film, and retroreflective coating.

9. The eye-tracking measurement device (100) as claimed in claim 1, wherein the projection device (110) is included in the goggles device (102) worn by the patient.

10. The eye-tracking device (100) of claim 9, wherein the projection device (110) is positioned between the two eyepiece apertures of the goggle device (102) and emits light in the patient's field of vision when the goggle device (102) is worn.

11. The eye-tracking measurement device (100) as claimed in claim 1, wherein the eye-tracking measurement device further comprises: Infrared light source (134); Image sensor (132); as well as A dichroic reflector (138) is configured to permit the transmission of visible light and the reflection of infrared light, and is positioned to optically communicate with each of the infrared light source (134), the image sensor (132), and the patient's eye.

12. The eye-tracking measurement device (100) of claim 1, wherein the micro-LED display device (112) is operable to emit light such that a two-dimensional motion simulation is projected onto the retroreflective screen (120).

13. A method for performing an eye-tracking measurement, the method comprising: Positioning the projection device (110) close to one or more patient eyes, the projection device (110) comprising: A microLED display device (112), the microLED display device comprising a light-emitting pixel array (300); and An optical lens (114) is positioned to communicate optically with the micro-LED display device (112); Operate the microLED display device (112) to emit light from the light-emitting pixel array (300); The light emitted by the microLED display device (112) is projected from the optical lens (114) onto at least a portion of the retroreflection screen (120) within the field of view of the optical lens (114); The optical lens (114) reflects the light projected onto the retroreflection screen (120) in the direction of one or more patient eyes; and In response to the observation of the reflected light by one or more patient eyes, the movement of the one or more patient eyes is observed.

14. The method of claim 13, wherein the light emitted by the microLED display device (112) is monochromatic green light.

15. The method of claim 13, wherein operating the microLED display device (112) to emit light from the light-emitting pixel array (300) includes operating the microLED device to emit light from at least one of the pixels of the pixel array or a group of adjacent pixels of the pixel array, such that the emitted light has an angular resolution of less than or equal to 0.5° on the retroreflective screen (120).

16. The method of claim 13, wherein operating the microLED display device (112) to emit light from the light-emitting pixel array (300) includes emitting light from at least one of the pixels of the pixel array or a group of adjacent pixels of the pixel array, such that the projection of the emitted light has a projection accuracy on the retroreflective screen (120) in the range of -0.5° to 0.5°.

17. The method of claim 13, wherein positioning the projection device (110) near one or more patient eyes includes positioning a goggle containing the projection device (110) on the patient's head.

18. The method of claim 13, wherein operating the microLED display device (112) to emit light from the light-emitting pixel array (300) includes emitting light such that a two-dimensional motion simulation is projected onto the retroreflective screen (120).

19. An eye-tracking measurement device (100), the eye-tracking measurement device comprising: Protective goggle device (102), the protective goggle device being configured to be worn on a patient's head, the protective goggle device comprising... Two eyepiece holes; Projection device (110), the projection device being positioned between the eyepiece apertures and comprising: A monochrome microLED display device (112) comprising a light-emitting pixel array (300) having a size of at least 120 horizontal pixels by 100 vertical pixels; and An optical lens (114) is positioned to optically communicate with the micro-LED display device (112) and is configured to project light within the field of view of the optical lens (114), the field of view being greater than or equal to 60° horizontally and greater than or equal to 50° vertically. Infrared light source (134); Image sensor (132); and A dichroic reflector (138), configured to allow the transmission of visible light and the reflection of infrared light and positioned to optically communicate with each of the infrared light source (134), the image sensor (132), and one or more patient eyes; and Retroreflection screen (120), the retroreflection screen being configured to overlap with the field of view of the optical lens (114), and comprising at least one of retroreflection fabric, retroreflection laminate, retroreflection film and retroreflection coating; The retroreflector (120) is configured to reflect light in the direction of one or more patient eyes; and The light emitted from a pixel of the light-emitting pixel array (300) or from at least one of a group of adjacent pixels of the light-emitting pixel array (300) and reflected back by the retroreflector screen (120) has an angular resolution of less than or equal to 0.5° on the retroreflector screen (120).

20. The eye-tracking measurement device (100) of claim 19, wherein light emitted from a pixel of the pixel array or at least one of a group of adjacent pixels of the pixel array has projection accuracy on the retroreflective screen (120) in the range of -0.5° to 0.5°.

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