Eye tracking device

Abstract

In this embodiment of the technology, a display screen is provided that displays an object to be viewed by the eye, and a camera is provided that photographs the eye when the eye is viewing the display screen. The device may include a reflector, a display screen positioned relative to the reflector so that the eye views the display screen reflected by the reflector, and a camera that photographs the eye when the eye is viewing the display screen, the camera being positioned to photograph the eye through the reflector. The device of the present invention may include a frame configured to position the display screen and camera relative to the eye during use. The frame may include a housing that occupies the display screen and camera within a light-controlled environment.

Description

Technical Field

[0001] This technical field relates to devices, systems, and methods for tracking eye movements. In particular, this field relates to eye tracking devices for obtaining information regarding eye tracking for use, for example, in evaluating medical conditions such as a person's ability to track an object, without limitation.

Background Art

[0002] The human eye is a complex and delicate organ used to perceive the surrounding world. The eye captures light and forms an image on the retina, which generates electrical signals that are sent to the brain and interpreted as visual information. Scientists and medical professionals have come to understand the importance of tracking eye movements in the diagnosis and treatment of various medical conditions. In particular, eye movements have been found to be a useful indicator of brain function, including the presence of certain medical conditions.

[0003] Examples of medical conditions that can be evaluated using eye movements include traumatic brain injuries such as mild traumatic brain injury (mTBI) and concussion. Mild traumatic brain injury is a complex neurobehavioral phenomenon caused by deformation of brain tissue due to head acceleration and can also be caused by mechanical forces that directly impact the skull. It can cause various symptoms such as headache, dizziness, fatigue, depression, anxiety, irritability, loss of consciousness, and cognitive impairment, and these symptoms can persist for days to years due to damage to the fine structure of axons and changes in neuro-metabolism, which disrupt the brain network. The effects of concussion can affect the brain's ability to control eye movements and may cause symptoms such as double vision, blurred vision, and coordination disorders.

[0004] The diagnosis of concussion is based on a combination of self-reported symptoms, physical examination, and neurological examination. One classical method is for a doctor to move a finger while looking at the patient and observe how the patient's eyes follow the movement. Such a method is prone to subjectivity and error, so an ideal clinical environment for conducting a careful examination may be desirable.

[0005] There are many situations outside of clinical settings where it may be necessary to quickly and accurately assess the possibility of a concussion. These situations include during contact sports such as football (NFL, soccer, Australian Rules Football), rugby, boxing, and combat sports, as well as at the scene of injuries such as road traffic accidents.

[0006] More reliable diagnostic methods, such as brain imaging CT scans and MRI scans, require expensive and bulky equipment that cannot be easily transported, making them unsuitable for on-site diagnoses in the situations described above.

[0007] Scientists are increasingly realizing that visually observing eye movements may also allow for the assessment of other types of medical conditions.

[0008] One example of an existing system useful for assessing concussions is Oculogica's EyeBOX®. This system requires a dedicated terminal and, although advertised as "portable," is actually about the size of a computer screen.

[0009] Another example, described in U.S. Patent No. 10,849,492, involves a device that uses the front-facing wide-angle camera of a smartphone held at arm length to capture images of the eyes. As a result, the eye images are captured with a low pixel count, making it difficult to accurately visualize and evaluate eye movements.

[0010] Another example is AR / VR headsets. However, in such headsets, the camera is positioned at a large angle to the eye to capture images. This reduces the resolution of the captured images of the eye, and consequently, the accuracy of evaluating eye movements decreases.

[0011] There is a growing need for tools that prioritize convenience, objectivity, and / or accuracy over existing diagnostic tools, and that can assess medical conditions through eye movements. [Overview of the project] [Problems that the invention aims to solve]

[0012] The objective of this technology is to provide an improved device, system, and / or method for tracking eye movements.

[0013] Alternatively, the purpose of this technology is also to provide a frame suitable for use in devices that track eye movements, such as the ability to track a target. Alternatively, the purpose of this technology is also to provide a useful alternative, at least to the public. [Means for solving the problem]

[0014] According to certain aspects of this technology, a device is provided for tracking eye movements, such as the ability to track a target.

[0015] In some forms, the device includes a display screen that displays an object for the eye to view, and a camera that images the eye when the eye is viewing the display screen. The device may include a frame configured to position the display screen and camera toward the eye during use. The frame may include a housing that accommodates the display screen and camera in a light-controlled environment, and the housing includes an aperture toward which the eye faces during use of the device.

[0016] According to one aspect of this technology, a device for tracking eye movements is provided, and this device, Reflector, The display screen is positioned relative to the reflector so that the display screen reflected by the reflector is visible to the eye when in use. This includes a camera for capturing images of the eye while the eye is viewing the display screen.

[0017] In certain configurations, the camera is positioned to photograph the eye through a reflector.

[0018] In some configurations, the reflector includes an aperture, and the camera is positioned to photograph the eye through the aperture when in use.

[0019] In an alternative configuration, the reflector may be semi-transparent, the camera may photograph the eye through the reflector, and the device is configured so that the eye can see the display screen reflected by the reflector. For example, the reflector may include a one-way mirror.

[0020] In certain embodiments, the device is configured such that the eye nearly fills the camera's field of view when viewing the display screen. In certain embodiments, the device further includes a lens positioned so that the camera photographs the eye through the lens. In certain embodiments, the lens may be a macro lens.

[0021] In certain configurations, the device is configured so that the camera is positioned almost directly in front of the eye, i.e., just in front of the eye, during use. In other configurations, the device may be configured so that the camera is positioned in front of and below the eye during use.

[0022] In certain forms, the reflector has a reflective surface configured to reflect light from a display screen towards the eye, and the reflective surface is concave in at least one plane.

[0023] In certain embodiments, the device further includes a frame configured to position a reflector, a display screen, and a camera toward the eye during use. The frame includes a housing that occupies the reflector, the display screen, and the camera within a light-controlled environment, and the housing includes an aperture toward which the eye faces during use of the device. In certain embodiments, the housing substantially prevents ambient light from entering the light-controlled environment during use, for example, light illuminating the eye may be provided by the display screen. The housing may take alternative or additional forms, for example, according to any other embodiment of the technology described below. In certain forms, the device includes one or more light sources. In some forms, the one or more light sources may include a display screen. Additionally or alternatively, the one or more light sources may include one or more light sources separate from the display screen. The one or more light sources can be diffused light sources. In some forms, the one or more light sources can be arranged on one or both sides of the eye during use. For example, the device may include two light sources arranged on the side of the eye during use, one light source is arranged outside the eye, and the other light source is arranged inside the eye. In some forms, the brightness of the one or more light sources can be adjustable. Additionally or alternatively, the frequency of the light generated by the one or more light sources can be adjustable.

[0024] In certain forms, the display screen is included as part of a first portable electronic device, such as a first smartphone.

[0025] In certain forms, the camera is included as part of a second portable electronic device, such as a second smartphone. In some forms, the display screen of the device for tracking eye movement can be the first display screen, and the second portable electronic device may include a second display screen for displaying an image captured by the camera. Additionally or alternatively, the camera can be configured to save and / or transmit an image captured by the camera for display and / or analysis at a location remote from the device, the eye, and / or the camera.

[0026] In some forms, the device can be configured such that the camera of the second portable electronic device is within the light control environment and the second display screen of the second portable electronic device is outside the light control environment.

[0027] In a particular form, the reflector is a first reflector, and the device may further include a second reflector. The eye is the first eye of the user, and the user may have a second eye. The display screen may be arranged with respect to the first and second reflectors such that, during use, the first eye views the display screen reflected by the first reflector and the second eye views the display screen reflected by the second reflector. The camera may be a first camera, and the device may further include a second camera for imaging the second eye when the second eye is viewing the display screen. The second camera may be arranged to image the second eye through the second reflector.

[0028] According to another aspect of the present technology, a frame suitable for use in a device for tracking eye movement is provided, the frame comprising a reflector holding structure for arranging a reflector, and a display screen holding structure for arranging a display screen with respect to the reflector such that, during use, the eye views the display screen reflected by the reflector when the reflector is arranged within the reflector holding structure, and a camera holding structure for arranging a camera for photographing the eye when the eye is viewing the display screen.

[0029] In a particular form, the camera holding structure is configured to arrange the camera, the reflector holding structure is configured to arrange the reflector, and the camera photographs the eye through the reflector during use. For example, the reflector may include an aperture, and the camera may be arranged to photograph the eye through the aperture during use.

[0030] In another example, the reflector is translucent, the camera can photograph the eye through the reflector, and the device is configured such that the eye can view the display screen reflected by the reflector. For example, the reflector may include a one-way mirror.

[0031] In certain configurations, the frame is configured such that the eye nearly fills the camera's field of view when viewing the display screen. In certain configurations, the frame further includes a lens holding structure for positioning the lens so that the camera can photograph the eye through the lens when in use. In certain configurations, the lens may be a macro lens.

[0032] In certain forms, the frame includes a housing that contains a reflector, a display screen, and a camera within a light-controlled environment, and the housing includes an aperture to which the eye is directed during use of the device. In certain forms, the housing substantially prevents light passing through other than the aperture from entering the light-controlled environment.

[0033] In certain configurations, the display screen holding structure may include a first slot for housing the display screen. The camera holding structure may include a second slot for housing the camera.

[0034] In certain embodiments, the housing includes a first housing section and a second housing section, which are configured to be assembled together to form a housing. In some embodiments, the first housing section includes a display screen holding structure. The first housing section may further include a camera holding structure. In some embodiments, the second housing section may include an aperture.

[0035] In certain configurations, the display screen is included as part of a first portable electronic device, such as a first smartphone. In such configurations, the first slot may be configured to accommodate the first smartphone.

[0036] In certain embodiments, the camera is included as part of a second portable electronic device (e.g., a second smartphone). In such embodiments, the second slot may be configured to accommodate the second smartphone. In some embodiments, the display screen of the device for tracking eye movements is the first display screen, and the second portable electronic device may include a second display screen for displaying images captured by the camera. In some embodiments, the housing may be configured such that the camera holding structure places the camera of the second portable electronic device within a light-controlled environment, while the second display screen of the second portable electronic device is outside the light-controlled environment.

[0037] In certain forms, the reflector holding structure may be a first reflector holding structure, and the reflector may be a first reflector. The device may further include a second reflector holding structure for positioning a second reflector. The eye is the user's first eye, and the user may have a second eye. The display screen holding structure may position the display screen relative to the first and second reflectors such that, in use, the first eye views the display screen reflected by the first reflector, and the second eye views the display screen reflected by the second reflector. The camera holding structure may be a first camera holding structure, and the device may further include a second camera holding structure for positioning a second camera for photographing the second eye when the second eye is viewing the display screen. The second camera holding structure may be configured to position the second camera so as to photograph the second eye through the second reflector.

[0038] Further embodiments of this technology should be considered in all its novel forms, and will become apparent to those skilled in the art from the following description, which illustrates at least one example of a practical application of this technology.

[0039] Hereinafter, with reference to the drawings, one or more embodiments of the present technology will be described for illustrative purposes only and without the intention of limitation. [Brief explanation of the drawing]

[0040] [Figure 1A] This is a frontal view of the human eye. [Figure 1B] Figure 1A is a cross-sectional view of eye 101 in the sagittal plane. [Figure 2] This is a schematic diagram of an eye-tracking device that is an example of this technology. [Figure 3] This is a schematic diagram of an eye-tracking device representing a further exemplary embodiment of this technology. [Figure 4A] This is a schematic diagram of an eye-tracking device representing a further exemplary embodiment of this technology. [Figure 4B] This is a schematic diagram of an eye-tracking device representing a further exemplary embodiment of this technology. [Figure 4C] This is a schematic diagram of an eye-tracking device representing a further exemplary embodiment of this technology. [Figure 5] This is a schematic diagram showing a part of an eye tracking device according to a further exemplary embodiment of the present invention. [Figure 6A] This is a diagram of the frame of an eye-tracking device according to one embodiment of the present invention. [Figure 6B] This is a diagram of the frame of an eye-tracking device according to one embodiment of the present invention. [Figure 6C] This is a diagram of the frame of an eye-tracking device according to one embodiment of the present invention. [Figure 6D] This is a diagram of the frame of an eye-tracking device according to one embodiment of the present invention. [Figure 7A] This figure shows the motion of an object on a display screen according to a specific embodiment of the technology of the present invention. [Figure 7B] This figure shows the motion of an object on a display screen according to a specific embodiment of the technology of the present invention. [Figure 8A] This is a schematic diagram showing the arrangement of light sources in an exemplary embodiment of this technology. [Figure 8B] This is a schematic diagram showing the arrangement of light sources in an exemplary embodiment of this technology. [Figure 9A] This is a schematic diagram of an eye-tracking device representing a further exemplary embodiment of this technology. [Figure 9B]This is a schematic diagram of an eye-tracking device representing a further exemplary embodiment of this technology. [Figure 9C] This is a schematic diagram of an eye-tracking device representing a further exemplary embodiment of this technology. [Figure 9D] This is a schematic diagram of an eye-tracking device representing a further exemplary embodiment of this technology. [Figure 10A] This is a schematic diagram of an eye-tracking device according to a further exemplary embodiment of the present invention. [Figure 10B] This is a schematic diagram of an eye-tracking device according to a further exemplary embodiment of the present invention. [Figure 11] This is a schematic diagram of an eye-tracking device according to a further exemplary embodiment of the present invention. [Modes for carrying out the invention]

[0041] 1. Eye The forms of this technology relate to devices, systems, and methods for tracking eye movements, such as the ability of the eye to follow an object. Several relevant aspects concerning the anatomy and movement of the eye are described below. However, the forms of this technology primarily concern tracking human eye movements.

[0042] In this specification, anatomical terms indicating position relative to the body, such as “superior,” “inferior,” “anterior,” and “posterior,” may be used. These are used as convenient labels to clarify the position of components of an exemplary form of the technology relative to the body of the patient or object of eye-tracking evaluation during the use of the technology, and to address the prospect that the patient may not necessarily be in a vertical (e.g., standing) position during the use of the technology. When using these terms to describe the relative position of a particular component, it should be understood that the device and its components do not necessarily have to be positioned that way relative to the object. The device may exist as the same device and embody a particular form of technology even when moved away from the body or oriented in a different direction.

[0043] 1.1. Anatomy of the Eye Figure 1A is a front view of a human eye 101, including the eye 104 and pupil 106. The movement of the eye 101 can be characterized by the movement of the eye 104 and / or pupil 106 along two mutually orthogonal axes, for example, the lateral axis relative to the body (i.e., the horizontal direction when the body is upright), indicated by the x-axis 107 in Figure 1A, and the vertical axis relative to the body (i.e., the vertical direction when the body is upright), indicated by the y-axis 108 in Figure 1A. These axes are also shown in Figure 1B, which is a cross-section of the eye 101 in Figure 1A in the sagittal plane (the vertical plane when the body is upright).

[0044] 1.2. Eye exercises The body has muscles (104) that control eye movement. The human eye (101) has extrinsic and medial eye muscles. The main function of the seven extrinsic eye muscles in each eye is to control eye movement and position. Each eye has three intrinsic eye muscles that control the movement of the lens and pupil dilation, which allows us to focus on nearby objects and control the amount of light entering the eye.

[0045] Eye movements are characterized by several types, including the following:

[0046] A saccade is a rapid, ballistic eye movement that shifts the gaze abruptly. The amplitude of a saccade varies from small movements, such as those seen when reading, to much larger movements, such as those seen when scanning a room. Saccades can be spontaneously induced, but they also occur reflexively when the eyes are open, even when fixating on an object.

[0047] Microsaccades are a type of fixation eye movement. These are small, twitching, involuntary, minute eye movements, similar to miniature versions of voluntary saccades. They usually occur during prolonged fixation to prevent fading.

[0048] A square wave jerk is a type of eye movement that occurs within approximately 200-500 milliseconds, characterized by a constant magnitude of movement away from or back to the point of focus.

[0049] • A pro saccadic saccadic motion is a saccadic movement directed toward an object, and usually occurs reflexively.

[0050] • An anti-saccade is a saccade movement away from an object, and is usually performed intentionally.

[0051] Drift is a slower, more gradual movement that occurs between microsaccades during fixation, although the brain mechanisms behind it are not fully understood.

[0052] Tremors are small, high-frequency fluctuations that occur between microsaccades.

[0053] • Fixation eye movements include, for example, microsaccades, square wave jerks, tremors, and drifts.

[0054] • Fixation: Fixation consists of slower, finer movements (fixational eye movements) that help to focus the eyes on an object and prevent perceptual fading. The duration varies, for example, between 50 and 600 milliseconds.

[0055] • Smooth Pursuit: This is a much slower eye movement tracking designed to keep a moving stimulus over the fovea. Such movements are under voluntary control in the sense that the viewer can choose whether or not to track a moving stimulus, and occur during saccades.

[0056] This form of technology can be used to track one or more of these types of eye movements.

[0057] Oculomotor disorders occur when there is some abnormality or impairment in normal eye movement, such as saccadic or smooth pursuit movements being inaccurate, interrupted, or irregularly timed relative to an object. Saccadic oculomotor disorders are movement disorders in which the eyes move excessively or insufficiently relative to an object, accompanied by saccadic eye movements for correction. Specific indices can be used to quantify oculomotor disorders. For example, saccadic gain is the ratio of eye movement to target position, and stimulus delay is the delay in response from the presentation of a target-shaped stimulus to the initiation of a motor command.

[0058] 1.3. Eye Tracking The present invention relates to devices, systems, and methods for “tracking” the movement of an eye 101. Unless otherwise explicitly stated in the context, the term “tracking” means the act of identifying the movement of an eye 101 over a period of time. Identifying the movement of an eye 101 makes it possible to characterize and analyze that movement. In certain forms, the movement of an eye 101 is tracked by visualizing the movement of the pupil 106. The pupil 106 is the aperture through which light enters the eye 101, and its position indicates the direction of the eye's line of sight. Eye tracking is, for example, tracking the eye’s ability to follow a moving object on a display screen visible to the eye. Errors in object tracking can be characterized and analyzed.

[0059] 2. Eye Tracking Devices / Systems Herein, exemplary embodiments of a device and / or system 200 for tracking eye movements according to a particular embodiment of the technology of the present invention are described. Such a device / system may be called an eye tracking device / system 200.

[0060] 2.1. Components of eye tracking devices / systems Here, we describe some components common to several exemplary forms of this technology. If these components are later described in the context of a specific form of eye-tracking device / system, it should be understood that the descriptions of the components in this section apply to any form of the technology unless explicitly stated otherwise.

[0061] 2.1.1. Display Screen In certain forms of this technology, the eye-tracking device 200 includes one or more display screens, e.g., a first display screen 210 and a second display screen 211. The display screens 210, 211 may include any devices configured to visually present information to the viewer. The information may be, for example, in the form of images. The display screens 210, 211 may be controllable to change the information displayed to the viewer. For example, a moving object may be displayed to the viewer, following various test protocols which will be described in more detail later. Since the range of eye movement may be important in detecting some medical conditions, in certain forms the displays may be positioned to occupy more than 100° of the field of view, and in some forms the eye-tracking device may be configured so that the displays occupy approximately 120° of the field of view. This means that the viewer must move their gaze over longer distances to follow the movement of an object (e.g., up, down, left, right) as the object may move on the display.

[0062] In certain exemplary forms, one or more of the display screens 210, 211 are electronic displays such as LCD, LED, or OLED screens. The information displayed on the display screens 210, 211 can be controlled by a controller or microprocessor included as part of the display screens 210, 211, or may be configured to control the display screens 210, 211 via a physical or wireless connection. In some forms, the display screens 210, 211 are included as part of an electronic device such as a portable electronic device 250, such as a smartphone, tablet, or laptop computer.

[0063] In some embodiments, each of the display screens 210 and 211 may be self-emissive, for example, they may include light-emitting elements such as LEDs. In other embodiments, either or both of the display screens 210 and 211 may be non-self-emissive, for example, the display screen may use electronic ink (e-ink) to display information. In such embodiments, another light source may be used to illuminate the display screen.

[0064] 2.1.2.Light source In certain forms, the eye-tracking device 200 may include a light source. The light source 350 may be a diffuse light source. The light source may be positioned in a location suitable for illuminating the eye 101 during use of the device 200. In certain forms, the light source may include a first display screen 210, and in some forms, the first display screen 210 may be the sole light source. This makes it possible to properly control and diffuse the illumination of the eye 101, covering a wide angle beyond 100° (e.g., about 120° to help avoid specular reflection), and consequently illuminating the eye 101 in a manner suitable for imaging.

[0065] For example, an image of moderately uniform intensity may be displayed across the entire display screen 210 to provide diffuse illumination and generate a uniform illumination distribution for the eye 101. Furthermore, the display screen 210 may be controlled, for example by selecting the image displayed on the display screen 210, so that the amount of light generated by the display screen 210 is sufficient to adequately illuminate the eye 101 in order to capture an image suitable for tracking the movement of the eye 101. For example, a well-illuminated eye would support the use of a camera 220 operating at a high frame rate, enabling imaging of very rapid movements of the eye 101, such as saccadic movements, and imaging the eye at a sufficiently high resolution.

[0066] In other embodiments of this technology, the eye tracking device 200 may include one or more light sources 350 separate from the display screen 210. In certain embodiments, the light sources 350 may be positioned in one or more aspects of the eye 101 during use, as shown, for example, in Figures 8A and 8B. In some embodiments (again, as shown in Figures 8A and 8B), two light sources 350 may be positioned on either side of the eye 101 during use, with one light source 350 positioned outside the eye and the other light source 350 positioned inside the eye. Positioning the light sources 350 in this manner helps to illuminate the eye without creating shadows from the eyelids or eyelashes. Furthermore, the light sources 350 do not project light directly into the pupil 106. In some embodiments, the light sources 350 may include a hood (e.g., an opaque barrier) to prevent light from the light sources 350 from directly illuminating the camera 220. This allows even very fast cameras, such as those exceeding 200 frames per second, to produce high-contrast images of the pupil 106 compared to the sclera or iris. Furthermore, it can reduce pupil constriction in users and alleviate discomfort for users with photosensitivity.

[0067] As shown in the example in Figure 8B, the device 200 may include one or more diffusers 352 to illuminate the eye 101 with diffused light. Each diffuser may be placed in front of one or more light sources 350 to diffuse the light emitted from the light source.

[0068] In certain configurations, the brightness of the light source (display screen 210 and / or separate light source 350) can be adjusted. Reducing the brightness of the light source can help improve patient comfort while using the eye tracking device 200, especially for light-sensitive patients. Furthermore, changing the brightness of the light can help generate different types of reflections from the iris pigment, which may be desirable for certain types of analysis of the eye 101. For example, in a configuration where the display screen 210 is a smartphone, the brightness can be adjusted in a conventional manner. In other configurations, the eye tracking device may include one or more light sources 350 in the form of LEDs. The LEDs may be configured to allow for brightness adjustment.

[0069] Furthermore, or alternatively, in certain forms, the frequency of light produced by the light source (display screen 210 and / or separate light source 350) can be adjusted. For example, the light source may be configured to selectively produce light from one or more parts of the electromagnetic spectrum, such as red light, blue light, and near-infrared light. The light source may be selected to produce white light. It is understood that this list of light spectra that can be produced by certain forms of light sources is not exhaustive. Varying the frequency of light may help produce different types of reflections from the pigments of the iris, which may be desirable for certain types of analysis of the eye 101.

[0070] 2.1.3. Camera In certain embodiments of this technology, the eye-tracking device 200 includes a camera 220. The camera 220 may include any optical device configured to capture and record visual images. The captured images may be displayed on a display screen, in some embodiments this display screen may be a second display screen 211 included as part of the eye-tracking device 200, and in other embodiments the camera may be configured to transmit images to a display screen for displaying the images, or to another device which may include memory for storing the images for display elsewhere. The images may be transmitted via a wired or wireless connection to, for example, a display screen located away from the eye-tracking device 200. The images may be displayed on the display screen in real time, near real time, or at a time later than when they were captured by the camera. In some embodiments the camera 220 includes memory configured to store visual images. In certain embodiments the camera 220 is a digital camera, and references to images may mean that data recorded by the camera represents the images.

[0071] In certain exemplary forms, the camera 220 is included as part of an electronic device such as a portable electronic device 250, such as a smartphone, tablet, or laptop computer. In such forms, the camera 220 includes a display screen 211 which can be configured to display images captured by the camera 220.

[0072] 2.1.4.Reflector In a particular form of this technology, the eye-tracking device 200 includes a reflector 230, which is a structure capable of reflecting light incident on it.

[0073] The reflector 230 may include a reflective surface 232, and in certain embodiments, the reflective surface 232 may include a mirror. As will be described later, in some embodiments of this art, the reflector 230 may include at least partially a unidirectional mirror (which may also be called a semi-silver mirror or translucent mirror), and the reflector 230 reflects light incident on the reflective surface 232 but transmits light incident on another surface. In other embodiments, the reflector 230 may include a prism configured to reflect incident light.

[0074] As will be explained in more detail below, in some forms the reflector 230 may be non-planar or curved, for example, concave in at least one plane.

[0075] 2.2. First Exemplary Embodiment of an Eye Tracking Device Figure 2 is a schematic diagram of an eye-tracking device 200 according to an exemplary embodiment of the present technology. The eye-tracking device 200 includes a display screen 210 and a camera 220. In the illustrated embodiment, both the display screen 210 and the camera 220 are included as part of a portable electronic device 250, such as a smartphone or tablet, but in other embodiments, the display screen 210 and the camera 220 may be provided as separate components. The device 200 is positioned so that the eye 101 can view the display screen 210, and the camera 220 can photograph the eye 101 when the eye is viewing the display screen 210.

[0076] In at least one example, the relative placement of the display screen, camera, and eye is configured to track eye movement as the camera tracks an object at substantially the same angle as the direction of the eye's line of sight, thereby providing accurate real-time data that helps detect medical conditions associated with delayed or irregular eye movements. Unlike conventional gaze tracking used to drive user interfaces, to successfully extract key indicators of eye movement, the camera 220 can operate at speeds exceeding 200 Hz with sufficient angular precision to track pupil movements of approximately 50 microns or more in certain configurations. Also, positioning the camera centered on the eye (i.e., substantially directly in front of the eye) means that the pupil can rotate with the eye and be visible when tracking an object on the display screen 210 over a wide range of eye movements. On the other hand, with a camera offset from this position, the pupil would be obscured in some directions due to the nature of the eye.

[0077] This configuration is simple, and only a single device, such as a smartphone or tablet, may be needed to implement the eye-tracking system. However, the image resolution of the eye 101 may be low because the device needs to be held sufficiently far from the eye so that the patient can focus on the display screen 210. In a typical adult eye, it can be difficult to focus on objects closer than approximately 200 mm from the eye. In this range, the camera of a typical smartphone or tablet will only use a subset of the available imaging field to image the eye 101, and therefore may not provide sufficient resolution for detailed eye tracking, especially for some of the small movements described above. On the other hand, if the display screen 210 is placed farther away from the eye 101, the proportion of the eye's field of view that the display screen occupies decreases as it is further away from the eye, thus limiting the range of movement the eye exhibits when tracking an object on the display screen. Depending on the symptoms of some medical conditions, it may be necessary to reproduce the full range of eye movement. Furthermore, in this technology, ambient light illuminates the eye 101, but fluctuations in the intensity and quality of ambient light can affect image quality.

[0078] 2.3. Schematic layout of further exemplary forms of eye tracking devices To address the aforementioned drawbacks in the technological configuration shown in Figure 2, other configurations of the technology utilize a reflector 230. This has the advantage of increasing the optical distance from the eye 101 to the display screen 210 while keeping the camera 230 relatively close to the eye 101 and therefore in a position to image at high resolution, as will be explained below.

[0079] Figures 3, 4A–4C, 5, 9A–9D, 10A, and 10B are schematic diagrams of an eye-tracking device 200 according to further exemplary embodiments of the present technology. As shown in these figures, the eye-tracking device 200 includes a display screen 210 and a reflector 230. The display screen 210 is positioned relative to the reflector 230 so that, when in use, the eye 101 views the display screen 210 reflected by the reflector 230, as shown by the rays of light in Figures 4C, 9A–9D, and 10A. In the embodiments shown in Figures 4A–4C, the display screen 210 may be included as part of a portable electronic device 250, positioned close to the patient's body so that the display screen 210 faces away from the patient. The reflector 230 is positioned in front of the eye 101 and further away from the patient than the display screen 210. The display screen 210 and the reflector 230 are positioned and oriented so that the eye 101 can see the reflection of the display screen 210 in the reflector 230, that is, so that light emitted from the display screen 210 is reflected by the reflective surface 232 of the reflector 230 and incident on the eye 101. In the illustrated embodiment, the reflector 230 is positioned such that the reflective surface 232 is generally facing the display screen 210 and the eye 101, that is, the display screen 210 and the eye 101 are positioned on the same side of the reflector 230.

[0080] As schematically shown in Figures 3 and 4A-4C, during use, the display screen 210 may be positioned above the eyes 101. For example, the display screen 210 may be positioned in front of the patient's forehead (e.g., directly in front). The display screen 210 may be tilted accordingly so that the eyes 101 can see the display screen 210 by reflection from the reflector 230, for example, as shown in Figures 4A-4C, the upper edge of the display screen 210 may be positioned in front of the lower edge of the display screen 210 (i.e., further from the patient's body). In other embodiments, the display screen 210 may be positioned in different positions and / or in different directions. For example, in some embodiments, the display screen 210 may be positioned below the eyes 101, for example, just in front of the patient's cheek. In other embodiments, such as shown in Figures 9A-9D and 10A, the display screen 210 may be positioned in front of the patient's body at a distance equivalent to the reflector 230, and may be positioned directly above or below the reflector 230. It is understood that the display screen 210 is properly oriented so that the eye 101 can see what is displayed on the screen reflected by the reflector 230, regardless of the position of the display screen 210. For example, as shown in Figures 9A-9D and 10A, if the display screen 210 is positioned directly above the reflector 230, the display screen 210 is oriented so that the plane of the screen is approximately parallel to the patient's cross-section (or horizontal plane), and the display screen 210 is positioned to face downwards toward the reflector 230 which is positioned directly below it.

[0081] In certain configurations, the reflective surface 232 of the reflector 230 may be concave, as shown in Figures 3 and 4A-4C. The concave shape of the reflective surface 232 helps to reflect light from the display screen 210 to the eye 101. This shape also helps to keep the overall size of the device 200 relatively compact, for example, allowing the viewer to focus on the display 210 while having a wide field of view of, for example, 120°, exceeding 100°. In other words, the concave reflector 230 makes the display screen 210 appear farther away from the eye 101 than it actually is, making it easier to focus. For example, in certain cases, the reflective surface 232 of the reflector 230 may be positioned at a distance of approximately 40-80 mm, for example 60 mm, from the eye 101 during use. The display screen 210 may be positioned at approximately the same distance from the reflector 230 during use. The optical properties of the reflector 230 allow the image to be restructured so that it is in focus over a wide field of view of the eye 101, for example, over approximately 100° or more, making it possible to test the viewer's visual range.

[0082] In some embodiments of this technology, the reflector 230 may be concave in multiple planes, while in other embodiments of this technology, the reflector 230 may be concave in a single plane. For example, the schematic diagrams of the device 200 in Figures 4A-4C, 5, and 9A-9D show a cross-section of the reflector 230 passing through a first plane oriented parallel to the sagittal (or longitudinal) plane of the body when the device 200 is in use. The reflector 230 has a concave cross-section in this first plane. The second plane may be oriented perpendicular to the first plane, for example, the second plane may be oriented horizontally, or it may be parallel to the cross-section (or horizontal plane) of the body. In this second plane, the reflector 230 may be a concave surface, or the reflector 230 may have a linear cross-section. In the example of Figure 3, the reflector 230 is also a concave surface in this second plane.

[0083] In certain configurations where the reflector 230 has a concave surface, the surface of the reflector may partially form part of an aspherical surface for reflecting a planar display suitable for the spherical human eye. Another part of the reflector's surface, or in other configurations the entire surface of the reflector, may form part of a parabolic surface to reflect, for example, parts of the display that are off-axis relative to the human eye. In one example, the central region of the reflective surface 232 of the reflector 230 has a radially distributed aspherical shape. For example, the aspherical surface may be an axisymmetric quadratic surface. This may make it easier for the eye 101 to focus on the plane of the display screen 210, even though the center of the display screen 210 is closer to the eye 101 than the edge of the display screen 210. Aspherical surfaces may also help reduce or eliminate other optical aberrations, such as spherical aberration and astigmatism, compared to simpler shapes of reflectors. Furthermore, the upper and lower regions (i.e., the bottom and top sides) of the reflective surface 232 may have a shape, such as a parabolic surface, where the curvature gradually increases toward the edge of the reflector 230. Light from the display screen 210 is reflected by the reflector 230, so that the eye 101 is at different distances from the top and bottom of the screen. The parabolic shape converts the different optical paths between the eye 101 and different parts of the display screen 210 into a common focal point.

[0084] An embodiment of the eye-tracking device 200 further includes a camera 220 for imaging the eye 101. The camera 220 is positioned appropriately so as to capture the eye 101 when the eye is viewing the display screen 210. In a particular embodiment of the eye-tracking device 200, as shown in Figures 4A and 4C, for example, the camera 220 is positioned to capture the eye 101 through a reflector 230. In this context, “through the reflector” means that the camera 220 is positioned on the opposite side of the reflector 230 from the eye 101, i.e., in front of the reflector 230, so that the light from the eye 101 passes from one side of the reflector 230 to the other side of the reflector 230 before being captured by the camera 220 (as opposed to referring to the light reflected by the reflector).

[0085] Depending on the form of the technology, the camera 220 can view the eye 101 through the reflector 230 in various ways. For example, in the forms shown in Figures 4A-4C, 9A, and 9B, the reflector 230 includes an opening 234, which may take the form of a small hole penetrating the reflector 230. The opening 234 is large enough for the camera 220 to photograph the eye 101 through the opening 234 without the reflector 230 obstructing the field of view, but may be larger than necessary to achieve this. The smaller the size of the opening 234, the less it obstructs the field of view of the display screen 210 of the reflector 230.

[0086] In another example, such as the embodiment shown in Figure 5, the reflector 230 may be semi-transparent, and the device 200 may be configured such that a camera 220 positioned on the opposite side of the reflector 230 from the eye 101 can photograph the eye 101 through the reflector 230 (i.e., light from the eye 101 passes through the reflector 230), and the eye 101 can view the display screen 210 reflected by the reflector 230 (i.e., light from the display screen 210 is reflected by the reflector 230). Here, “transparent” refers to the ability of light to pass through the material forming the reflector 230, as opposed to a reflector 230 having an opening through which light can pass, as shown in Figure 4A. In some embodiments, the entire reflector 230 may be semi-transparent, while in other embodiments, only a portion of the reflector 230, i.e., the area of ​​the reflector 230 through which the camera 220 views the eye 101, may be semi-transparent. The device may be configured so that the reflector functions semi-transparent depending on the lighting conditions on both sides of the reflector 230. For example, the illumination behind the reflector 230 (i.e., the space between the reflector 230 and the eye 101) is relatively brighter than the illumination in front of the reflector 230 (i.e., the space between the reflector 230 and the camera 220). As will be described later, appropriate illumination conditions can be established by providing a housing 262 that houses the device components in a light-controlled environment. In certain embodiments, the reflector 230 may include a one-way mirror, also called a half-mirror. In some embodiments, the mirror may have a silver-plated front surface as seen from the display screen 210 (i.e., the reflective surface 232 may be silver-plated) and a coating on its rear surface (i.e., the surface of the reflector 230 opposite the reflective surface 232) with an anti-reflective color. This can reduce chromatic aberration and ghosting that appears in the image on the display screen 210 as light refracts from the air to the mirror material and back into the air.

[0087] To analyze eye movements, it is useful for the camera 220 to capture images of the eye 101 with the highest possible resolution and frame rate within the limitations of the physical and optical configuration of the device 200. To achieve this, the device 200 may be configured such that the eye 101 nearly fills the field of view of the camera 220 when viewing the display screen 210, for example, as shown by the indicator rays in Figures 4B, 5, and 9A-9D. In certain forms, the device 200 further includes a lens 225 positioned so that the camera 220 photographs the eye 101 through the lens 225, as shown, for example, in Figures 4A-4C, 5, 9A, and 9B. For example, the lens 225 may be positioned directly in front of the camera 220. In the examples of Figures 4A-4C, 9A, and 9B, the lens 225 is positioned within the aperture 234, but it could also be positioned in front of the reflector 230, i.e., between the reflector 230 and the camera 220. In the example in Figure 5, the lens is positioned in front of the reflector 230, i.e., between the reflector 230 and the camera 220. In some forms, the lens 225 may be provided as part of the camera 220. In some forms, the lens 225 may be a macro lens. This may allow the camera to ensure that the field of view required for the eye 101 fills the field of view of the camera 220. For example, some existing smartphone cameras may require the addition of an additional corrective optical element (such as the shape of a macro lens) to enable macro-style close focusing so that the viewer's eye is in focus and extends to fill the camera's field of view. In one example, the focal range of a smartphone camera is approximately 20 cm to approximately infinity, and the macro lens may be configured to adjust this focal range from approximately 2 cm to approximately 20 cm. As a result, the camera 220 with such a lens may be able to focus on the user's eye at a distance of approximately 40-80 mm from the camera. When using a dedicated camera sensor, an appropriate lens may be selected considering the focal range of the viewer's eye position relative to the camera (e.g., 40-80 mm from the eye in some examples).

[0088] In an example using a typical smartphone model as camera 220, camera 220 might include a sensor with a width of approximately 1,920 pixels. If device 200 is configured so that the eye 101 nearly fills the field of view, based on a typical eye width of 24.2 mm, each pixel would capture a 12.6-micron portion of the eye at the center of the field of view. Higher precision can be achieved through image processing techniques such as subpixel tracking. For comparison, a typical microsaccade can be as small as 15 arcminutes or 0.25°. For an eye with a width of 24.2 mm, this corresponds to approximately 53 microns. Therefore, a lower pixel resolution may be required to successfully track small eye movements such as microsaccades.

[0089] In the examples of Figures 3, 4A–4C, and 5, the eye-tracking device 200 is configured such that the camera 220 is positioned almost directly in front of the eye 101, i.e., just in front of the eye 101, during use. This can help to obtain a clear image of the eye and to keep the eye within the full field of view of the camera 220. Another example is shown in Figure 9A. In this example, the eye-tracking device is configured such that the camera 220 is positioned in front of and below the eye 101 during use. As a result, the camera 220 is positioned so that the line of sight is slightly tilted upward. In this embodiment, the entire eye-tracking device 200 may be positioned relatively lower compared to the eye-tracking device 200 in Figures 3, 4A–4C, and 5. That is, compared to the devices in Figures 3, 4A–4D, and 5, the eye-tracking device 200 may rotate downward around an axis aligned perpendicular to the sagittal plane of the body. The display screen 210 may be positioned lower than in other configurations. For example, in the configuration of Figure 9A, the display screen 210 may be positioned above the eye 101, for example, almost directly in front of the top of the orbit. In this configuration, the eye tracking device 200 may be able to capture a wider range of downward eye movement compared to upward movement. For example, the eye tracking device 200 may be configured to capture eye movement of up to approximately 30° upward and up to approximately 50° downward. This may be desirable because the range of motion of the human eye is generally asymmetrical. In such configurations, it may be desirable to position the camera 220 below the eye 101 to avoid the camera's field of view being obstructed by the patient's eyelid.

[0090] In the embodiment of the technology shown in Figure 9B, the display screen 210 is positioned substantially horizontally with respect to the eye 101. That is, when the eye-tracking device 200 is in use, the display screen 210 can be substantially parallel to the horizontal plane (also called the cross plane) of the body of the object being tracked. In this embodiment, the camera 220 can be positioned substantially in front of the eye 101, i.e., just in front of the eye 101. This makes it possible to position the camera 220 so that its optical axis is substantially parallel to the plane of the display screen 210. As a result, the camera 220 and the display screen 210 can be positioned substantially perpendicular to each other. This arrangement simplifies the manufacturing of the frame 260 that holds the two components substantially perpendicular to each other, and thus makes it easier to position the display screen 210 and camera 220 within the frame 260, as will be discussed later.

[0091] In the form of the technology shown in Figure 9B, the display screen 210 is positioned nearly horizontally to the eye 101, and the reflector 230 can be appropriately configured to reflect light from the display screen 210 to the eye so that the eye 101 can view the display screen 210 as a nearly distortion-free planar image. In this orientation, the distance between different parts of the display screen 210 and the reflector 230 can vary; for example, the front part of the display screen 210, which is farther from the eye 101, will be closer to the reflector 230 than the rear part of the display screen 210, which is closer to the eye 101. In certain forms, this result may be achieved by a reflector 230 with an aspherical shape, which is a modified linear paraboloid. The schematic diagram in Figure 9D shows several different shapes of the reflector 230 in such a configuration. Reflector 230a has an aspherical surface, and reflector 230b has a linear perpendicular paraboloid, that is, the parabolic shape may exist in a vertical cross section (i.e., a cross section parallel to the median sagittal plane of the user's body) as shown in Figure 9D, but may or may not exist in a horizontal cross section (i.e., a cross section parallel to the cross-section of the user's body). Reflector 230c has a surface that combines these two shapes, i.e., an aspherical surface and a linear perpendicular paraboloid. When an appropriate shape is selected, the display screen 210 can be viewed as a planar image by the eye 101, as shown in the virtual image 212 in Figure 9D. In contrast, the schematic diagram in Figure 9C shows a similar arrangement in which only reflector 230a is aspherical. In this arrangement, in order to obtain the same virtual image 212, the display screen 210 must be placed between the eye 101 and reflector 230a, and the eye 101 must view it through the aperture of reflector 230a. For example, the advantage of the arrangements shown in Figures 9A, 9B, and 9D is that the eye 101 does not need to view through the display screen 210, so the display screen 210 can be provided using a conventional device, such as a personal electronic communication device (such as a smartphone).

[0092] Furthermore, high-resolution images and high frame rates can be achieved by ensuring that the eye 101 is adequately illuminated by a dedicated light source, ambient light, or a combination thereof. The faster the camera speed, the shorter the exposure time, and therefore more light is required. Also, high-resolution sensors require more light to produce a good image compared to low-resolution sensors of the same size because the light-receiving area is smaller. In certain configurations, device 200 includes a light source that illuminates the eye 101 during device use.

[0093] 2.4. Frame / Housing The eye tracking device 200 is schematically shown in Figures 3, 4A–4C, 5, 9A–9D, 10A, and 10B. In certain embodiments of this technology, the eye tracking device 200 further includes a frame 260, which is configured to position other components of the eye tracking device 200 relative to one another, although this is not shown in these figures.

[0094] Generally speaking, the frame 260 includes multiple structures that hold each of the other components of the eye-tracking device 200 in a desired relative position. The multiple structures are assembled as the frame 260. The frame 260 may include a reflector holding structure 264 for positioning the reflector 230 as described above, a display screen holding structure 266 for positioning the display screen 210 relative to the reflector 230 when the reflector is positioned within the reflector holding structure 264 as described above, and a camera holding structure 268 for positioning the camera 220 as described above.

[0095] An example of a frame 260 according to one embodiment of this technology is shown in Figures 6A to 6D. In this embodiment and other specific embodiments, the frame 260 includes a housing 262. The housing 262 may house one or more other components of the eye-tracking device 200. For example, in the example in Figures 6A to 6D, the housing 262 may house a reflector 230, a display screen 210, and a camera 220. The housing 262 defines an internal chamber in which these components are housed. The housing 262 may also include an aperture 270 into which the eye 101 is directed during use of the eye-tracking device 200. The aperture 270 is appropriately positioned within a portion of the housing 262 so that when the eye 101 looks through the aperture 270 into the internal chamber of the housing 262, the display screen 210 reflected by the reflector 230 can be seen. For example, the aperture 270 may be positioned on the wall of the housing facing the eye 101 when the device 200 is in use, and is also referred to as the rear wall 282 in the following description. The aperture 270 may be of an appropriate size so that the eye 101 can see through it, but not so large as to allow excessive ambient light into the internal space around the eye 101. In some embodiments, the aperture 270 is circular, but in other embodiments, the aperture 270 may be of a different appropriate shape.

[0096] The housing 262 may be configured such that the internal chamber becomes a light-controlled environment, i.e., the amount of light in the chamber is limited and controlled. In some embodiments, the housing may be configured to substantially prevent ambient light from entering the light-controlled environment within the internal chamber. As described above, in some embodiments, the housing may include an aperture 270, which may be the only way for ambient light to enter the internal chamber, and if the device 200 is in use and the eye 101 is positioned near the aperture 270 and at least partially obstructs it, ambient light can be restricted from entering through the aperture 270. In some embodiments, as shown, for example, in Figures 6A to 6D, one or more of the first display screen 210, the second display screen 211, and the camera 220 may need to be positioned in place to form or contribute to the formation of the walls of the housing 262 when the eye-tracking device 200 is assembled, and to substantially prevent ambient light from entering the internal chamber of the housing 262. The light-controlled environment can assist in the operation of the eye-tracking device 200. For example, by preventing ambient light from substantially entering the internal chamber, ambient light is also substantially prevented from entering the camera 220, so that the illumination within the camera's field of view is limited to that lit inside the housing 262.

[0097] As described above, device 200 may include a light source. The light source may be housed within the housing 262 and positioned to illuminate the eye 101 during use of device 200. In certain embodiments, the light source within the housing 262 includes a first display screen 210, and in some embodiments, the first display screen 210 may be the sole light source. Since the display screen 210 is the sole light source within the housing 262, if the reflector 230 is translucent and part of the eye-tracking device in the form shown in Figure 5, it becomes easier to allow the display screen 210 to display an image to the eye 101 and at the same time allow the camera 220 to photograph the eye 101 through the reflector 230. In other embodiments, one or more light sources 350 may be light sources other than the first display screen 210. In such embodiments, the light sources may be positioned near the eye 101 and closer to the eye 101 than the reflector 230, thereby facilitating the unidirectional illumination of the reflector 230.

[0098] In the forms of technology shown in Figures 6A-6D, the housing 262 includes a front wall 280, a rear wall 282, a first side wall 284, a second side wall 286, an upper wall 288, and a lower wall 290. As previously mentioned, labels such as “front” and “rear” refer to the relative positions of the walls when tracking the movement of the eye 101 using the device 200, although it should be understood that the device 200 may be removed from the body or oriented in different directions while remaining the same device. The walls 280, 282, 284, 286, 288, and 290 may be formed together to form an optically controlled environment within the housing 262, as described above. As shown in Figures 6A and 6C, the housing 262 may include a camera holding structure 268 such that the camera 220 is held adjacent to or forming part of the front wall 280. For example, the camera holding structure 268 may include one or more camera slots 269 into which the camera 220 can be slid to properly position the camera 220 within the housing 262. In the illustrated embodiment, the camera holding structure 268 includes camera slots 269 along the opposite side of the front wall 280, holding each end of the camera 220 when the camera is inserted into the camera slot 269. In other embodiments, one or more camera slots 269 may be provided along the upper and lower edges of the front wall 280 and configured to hold the top and bottom of the camera 220. The camera slots 269 may be set to an appropriate size and spacing to hold, for example, one or more widely used smartphone models.

[0099] The front wall 280 may include a front wall gap 281, which is an air gap within the area of ​​the front wall 280. When positioned within the camera holding structure 268, the camera 220 fills the front wall gap 281 and, together with the rest of the front wall 280 around the front wall gap 281, forms the front wall 280. As in the examples in Figures 6A-6D, the camera 220 may occupy a large portion of the area of ​​the front wall 280 when positioned in place. One advantage of the front wall gap 281 is that the user can access the front side of the camera 220. If the user interface or control buttons of the camera 220 are located on the front of the camera 220, the front wall gap 281 allows the user to operate them while holding the camera 220 in place. If the camera 220 has a display screen 211, the front wall gap 281 allows the user to view the display screen 211 while the camera 220 is held in the camera holding structure 268. In other words, device 200 can be configured such that the camera 220 of the second portable electronic device is within the light-controlled environment, and the second display screen 211 of the second portable electronic device is outside the light-controlled environment.

[0100] As shown in Figures 6A and 6C, one of the camera slots 269 may include a slot opening 292 in the rear wall of the camera slot 269. The slot opening 292 can be positioned and sized appropriately so that when the camera 220 is held in the camera holding structure 268, the lens of the camera 220 may be positioned adjacent to the slot opening 292, allowing light to pass through the opening to the camera 220. The slot opening 292 may be appropriately positioned to fit, for example, a widely available smartphone model.

[0101] As shown in Figures 6B and 6D, the rear wall 282 of the housing 262 may include the aperture 270 described in more detail above. The aperture 270 may be positioned in the rear wall 282 such that it is located approximately in front of the camera 220 when the camera 220 is held by the camera holding structure 268. In the example shown, the aperture 270 is located close to one end of the rear wall 282 and approximately in front of the slot opening 292 of the front wall 280.

[0102] In certain morphologies, the anterior wall 280 and the posterior wall 282 are nearly parallel to each other and may be oriented nearly parallel to the coronal (or frontal) plane of the body when the eye tracking device 200 is in use.

[0103] In certain embodiments, the display screen holding structure 266 is included in the housing such that the display screen 210 is held adjacent to or forms part of another wall, such as a rear wall 282, an upper wall 288, or a lower wall 290. In the examples of Figures 6A-6D, the rear wall 282 includes the display screen holding structure 266. In this example, the rear wall 282 includes first and second rear wall portions 282a and 282b, where the first rear wall portion 282a is positioned above the second rear wall portion 282b during use, but in other embodiments, the first rear wall portion 282a may be positioned below the second rear wall portion 282b during use. The second rear wall portion 282b includes an aperture 270 and may be oriented substantially parallel to the front wall 280 as described above. The first wall portion 282a may be oriented at a non-zero angle with respect to the second rear wall portion 282b. Furthermore, the first wall portion 282a may include a display screen holding structure 266. Thus, in certain embodiments, the display screen holding structure 266 holds the display screen 210 at a desired angle, for example, the angle schematically shown in Figure 3.

[0104] In certain embodiments, as shown, for example, in Figures 6A and 6C, the display screen holding structure 266 may include one or more display screen slots 267 into which the display screen 210 can be slid to properly position the display screen 210 within the housing 262. In the illustrated embodiment, the display screen holding structure 266 includes display screen slots 267 along opposing aspects of the first rear wall portion 282a, holding each end of the display screen 210 when the display screen is slid into the display screen slots 267. In other embodiments, one or more display screen slots 267 may be provided along the upper and lower ends of the first rear wall portion 282a and configured to hold the upper and lower parts of the display screen 210. The display screen slots 267 may be set to an appropriate size and spacing to, for example, hold one or more widely used smartphone models.

[0105] The first rear wall portion 282a may include a rear wall gap 283, which is an air gap within the region of the rear wall 282. When placed within the display screen holding structure 266, the display screen 210 may fill the rear wall gap 283, forming the first rear wall portion 282a together with the rest of the first rear wall portion 282a around the rear wall gap 283. As in the examples in Figures 6A-6D, the display screen 210 may occupy a large portion of the area of ​​the first rear wall portion 282 when placed in a predetermined position.

[0106] In other embodiments, the display screen 210 may be held adjacent to other walls, such as an upper wall 288 or a lower wall 290. In such embodiments, each wall includes a display screen holding structure 266, which may instead include a first wall portion and a second wall portion, as described above with respect to the rear wall 282.

[0107] The housing 262 may include a reflector holding structure 264 for holding the reflector 230 in the aforementioned position. The reflector holding structure 264 may be formed on the inside(y) of one or more walls of the housing 262. Alternatively, the reflector 230 may be held in place by abutting against the inside(y) of one or more walls of the housing 262. For example, in the examples of Figures 6A-6D, the reflector 230 may be positioned within the housing with its upper end abutting against the downward-facing inner surface of the upper wall 288 and its lower end abutting against the upward-facing inner surface of the lower wall 290.

[0108] In certain embodiments, the housing 262 may include a first housing section 263a and a second housing section 263b. The first housing section 263a and the second housing section 263b may be configured to be assembled together to form the housing 262. In different embodiments of the technology, different combinations of the front wall 280, rear wall 282, first side wall 284, second side wall 286, top wall 288, and bottom wall 290 may constitute the first and second housing sections.

[0109] For example, in the embodiment of the technology shown in Figures 6A-6D, the first housing portion 263a consists of a front wall 280, part of a first side wall 284, part of a second side wall 286, a first rear wall portion 282a, and an upper wall 288, while the second housing portion 263b consists of a second rear wall portion 282b, another part of the first side wall 284, another part of the second side wall 286, and a lower wall 290. Other embodiments of the technology have different configurations. In some embodiments, the housing components may be configured to allow, or make easier, the insertion of the camera 220 into the camera slot 269 and / or the insertion of the display screen 210 into the display screen slot 267 by removing the first housing portion 263a from the second housing portion 263b. The ability to separate the first and second housing portions facilitates cleaning of the eye tracking device 200 and also simplifies the manufacturing of the device 220. For example, the two housing portions may be designed to be easily molded.

[0110] The embodiments of the technology shown in Figures 10A and 10B are examples of device 200 in which the frame 260 is configured such that the display screen 210 and the camera 230 are perpendicular to each other, that is, the optical axis of the camera 220 is positioned approximately parallel to the plane of the display screen 210. In this embodiment, the frame 260 includes a display screen holding structure 266 and a camera holding structure 268 (not shown) configured to position the display screen 210 and the camera 220 in a predetermined orientation. In some embodiments, the frame 260 may include a housing 262 including a camera slot for holding the camera 220 and a display screen slot for holding the display screen 210, as described above. In other embodiments, other suitable mechanisms may be used to position the display screen 210 and the camera 220 in the aforementioned orientation and position.

[0111] The schematic layout of the light source 350 relative to the eye 101 shown in Figure 8A can be realized by positioning the light source 350 on the front (i.e., inner) side of the rear wall portion 282b on either side of the aperture 270, as in the exemplary forms shown in Figures 6A to 6D. In another form, the light source 350 may be positioned inside the first side wall 284 and inside the second side wall 286. In some forms, such as the examples shown in Figures 10A and 10B, one or more light sources 350 may be housed within an illumination unit 354. The illumination unit 354 may be located on the front of the housing 262, i.e., the side closer to the eye 101 during use, and in front of the aperture 270. The illumination unit 354 may be configured so that the eye 101 can view the first display screen 210 reflected by the reflector 230 through the illumination unit 354. A further aperture may be provided on the side of the illumination unit 354 closer to the eye 101. As shown in Figure 8B, one or more light sources 350 may be arranged in one or more ways of the lighting unit 354, for example, one light source 350 may be arranged on one side of the lighting unit 354 and another light source 350 may be arranged on the other side of the lighting unit 354.

[0112] In some embodiments, as shown in Figures 10A and 10B, for example, the device 200 may include an eyepiece lens 271 that helps the user position their eye 101 appropriately for viewing through the aperture 270 of the housing 262. Furthermore, the eyepiece lens 271 helps position each eye using the device 200 in a similar position, thereby facilitating the capture and analysis of eye-tracking data, enabling, for example, more consistent and comparable analysis. In the illustrated example, the eyepiece lens 271 is mounted in front of the illumination unit 354 (i.e., the side of the illumination unit 354 that faces the eye 101 when in use), and the eye 101 can direct its line of sight through the eyepiece lens 271, the illumination unit 354, and the aperture 270 on the front of the housing 262. In other embodiments of the device 200 that do not include the illumination unit 354, the eyepiece lens 271 may be provided directly on the front of the housing 262. The eyepiece lens may include one or more hoods 274, for example, a right hood 274a and a left hood 274b. Each hood 274 is shaped to contact the area around the eye 101 on the patient's face, so that the hood prevents ambient light from entering the housing 262 through the aperture 270 while allowing the user to comfortably look into the device 200. In some embodiments, as shown, for example in Figure 10B, the eyepiece 271 may include an eyepiece frame 272 to which one or more hoods 274 are attached. One or more apertures may be formed in the eyepiece frame 272 that the eye 101 will gaze upon when using the device 200. The hoods 274 may be attached to the eyepiece frame 272 around each aperture. In some embodiments, as shown, for example in Figure 10B, the eyepiece 271 may include an opaque cover 276 that blocks light from passing through one of the apertures of the eyepiece frame 272, preventing the user from seeing out with one eye when using the device 200. This can help ensure that when using the device, the user's vision is solely through the eyes 101 (staring at the device 200), and can also help the user know where to position their eyes.In some configurations, the eyepiece 271 can be detached from the housing 262 (or the illumination unit 354, if present) and reattached in an inverted orientation. This allows the user's other eye to look into the device 200 and block the view of the other eye, thereby enabling tracking of the movement of the user's other eye. Any suitable mechanism can be used to temporarily connect the eyepiece to the rest of the device 200; in one example, a magnet / magnetic element arrangement can be used to form a magnetic connection between the eyepiece 271 and the rest of the device 200. The magnet / magnetic element can be arranged so that the eyepiece 271 is connected in the desired orientation.

[0113] In some forms, the housing 262 may include one or more openings, in addition to the aperture 270, to allow cables to pass through the walls of the housing and connect to one or more components inside. The cables can be used to supply power to and / or data to electronic devices within the housing 262.

[0114] In certain configurations, the housing 262 can take the form of a headset suitable for displaying virtual reality (VR) and / or augmented reality (AR) content to the user. For example, the display screen 210 may be configured to display other content that may be part of a VR or AR experience to the user. In some configurations, there may be an additional display screen positioned generally in front of the patient and in front of the reflector 230, configured to display content to the user in the form of a VR device. In another configuration, the front area of ​​the device 200 is mostly transparent or contains gaps, allowing the user to directly view the surrounding environment in front of their eyes. If the display screen 210 displays images that the user sees through the reflection from the reflector 230, the device 200 can function as an AR device because these images are visible in addition to the surrounding environment. In such configurations, the device 200 may further include a head-mounting structure to position and stabilize the device 200 on the user's head, such as the arrangement of straps or other headgear components.

[0115] 2.5. Variations of the double-headed type The forms of technology shown in Figures 6A–6D, 10A, and 10B are suitable for tracking the movement of one eye. While tracking the movement of one eye may be suitable for evaluating some medical conditions (such as concussions), in evaluating other medical conditions, there may be merit in simultaneously tracking the movement of both eyes of a patient.

[0116] In certain forms of this technology, an eye-tracking device 200 suitable for simultaneously tracking the movement of both eyes may be provided, for example, as shown in Figure 11. Such forms may be called “binocular” or “stereo” variations of the device. In such forms, the device 200 includes a single display screen 210 and two reflectors 230, each reflector 230 positioned to reflect light from the display screen 210 to each of the patient’s eyes 101. For example, the two reflectors 230 may be positioned side by side within a housing 262 and positioned to reflect light from the display screen 210 to each eye 101, so that one eye views the display screen 210 reflected by the first reflector and the other eye views the display screen 210 reflected by the second reflector. In some forms, each eye may view only its respective portion of the display screen 210, the display screen 210 may be configured to display two images, these images may be positioned side by side on the display screen, and each image may be displayed to one eye. In some embodiments, the housing 262 may include an inner wall (not shown) that divides the internal volume of the housing 262 into two chambers. The inner wall may be opaque and configured to substantially prevent light transmission between the chambers.

[0117] In line with the above description, cameras 220a and 220b may each include a second display screen 211 for displaying images captured by their respective cameras. Alternatively, or additionally, cameras 220a and 220b may be configured to transmit images to another device which may include a display screen for displaying images, or memory for storing images for display elsewhere. Images may be transmitted via wired or wireless connections such as Bluetooth, WiFi, or NFC.

[0118] In this embodiment, the eye-tracking device 200 further includes two cameras 220a and 220b, each camera positioned to capture each eye when the eye is viewing the display screen 210. For example, as shown in Figure 11, cameras 220a and 220b are positioned side by side on the side of the housing 262 opposite to the eye 101 during use, and each camera has a field of view through its respective aperture in the front wall 280 of the housing 262. That is, the front wall 280 of the housing 262 may have two apertures formed laterally spaced apart so that each of the two cameras 220a and 220b can capture each eye through one of the reflectors, respectively. In such an embodiment, the device 200 includes two camera-holding structures, each camera-holding structure positioning one camera to capture each eye as described above. Alternatively, the eye-tracking device 200 includes a single camera 220, and the device 200 may further include an optical assembly configured to create an image of each eye on the same camera sensor. For example, an optical assembly may include multiple Porro prisms, such as four Porro prisms arranged similarly to a binocular. In other forms, an optical assembly may include another arrangement of prisms, lenses, and / or mirrors.

[0119] An eye-tracking device 200 in the form shown in Figure 11, and examples of similar binocular variants, include a housing 262 with two apertures 270 (not shown in Figure 11) in the rear wall 282 facing the user's eyes during use, each aperture being appropriately positioned to be visible through each eye during use, for example, the apertures 270 may be positioned laterally spaced within the rear wall 282. Alternatively, a single aperture 270 large enough to be visible to both eyes may be formed in the rear wall 282. In some forms, an illumination unit 354 as described above may be provided on the front of the housing 262. In some forms, an eyepiece lens 271 may be provided on the front of the housing 262 or the illumination unit 354. The eyepiece lens 271 may include a frame 272 and one or more hoods 274 suitable for binocular viewing. For example, two apertures are formed in the frame 272, with each aperture positioned in front of each eye during use of the device. As shown in Figure 11, the device 200 includes a single hood 274 configured to rest against the area around both eyes of the user's face during use, and the hood is configured to allow the user to comfortably look into the device 200 while blocking ambient light from entering the housing 262. Alternatively, the device may include two such hoods configured to rest against each eye during use.

[0120] It should be understood that embodiments of eye-tracking devices by other forms of technology may also be applicable to embodiments of eye-tracking devices configured to track the movement of two eyes simultaneously. For example, the camera(s) 220 may be configured to view the eye(s) 101 through the reflector(s) 230, similar to the method described above. Even if not explicitly stated, other embodiments of previous forms of the Art may also be applicable to this binocular form of the Art.

[0121] 3. Operation of the eye tracking device To use the eye-tracking device 200 according to this embodiment of the technology, the reflector 230, the display screen 210, and the camera 220 are arranged as described above, and the eye 101 is positioned so that the eye 101 views the display screen 210 and the camera 220 captures an image of the eye. For example, in the case of the eye-tracking device 200 including a housing 262 as shown in Figures 6A to 6D, the reflector 230 is inserted into the housing 262, and the display screen 210 and camera 220 are inserted into the display screen slot 267 and camera slot 269, respectively. For example, a smartphone may be inserted into each slot. The display screen and camera are activated, and the eye 101 is directed towards the aperture 270.

[0122] The display screen 210 may be configured to display any appropriate information to the eye 101, such as one or more images including a video, to facilitate the evaluation of eye tracking. Any appropriate image can be displayed, and the specific form of the technology is not limited by the nature of the image displayed on the display screen 210. The nature of the image may depend on the medical condition being evaluated by tracking eye movements. In one example, as shown in Figures 2, 7A, and 7B, the display screen generally displays, in monochrome, an object 303 moving around a motion path 305. The object 305 may be any icon, such as a dot. The motion path 305 may be elliptical, circular, sinusoidal, sawtooth, or any other motion path deemed suitable for testing the patient's eye tracking. In the exemplary display screen 210 of Figure 7B, the position of the object 303 is indicated by consecutive positions 303a, 303b, 303c, and 303d along its motion path 305 over time. The same figure also shows the projection of the path onto the X and Y axes over time. The elliptical motion path 305 of the object 303 in this example allows the eyes to move in both the X direction (corresponding to points 303a and 303c) and the Y direction (corresponding to points 303b and 303d) to train the range of eye movement. In some examples, the motion path 305 may be modified to be flat or off-axis to suit certain test conditions. The repeated movement of the object 303 along the motion path 305 smoothly trains the human eye-brain interface. In the illustrated example, the X and Y axis movements are sinusoidal, but in other examples, they can be changed to sawtooth or square waves. In some forms, varying the speed and amplitude of the object 303's movement on the display screen 210 over time can increase the cognitive and physiological load on the subject. Increased cognitive stress may lead to increased symptom severity, and speeding up the movement may help identify the limit. In some forms, the subject is tested over a series of trials, and the movement speed of the object 303 may be gradually increased with each trial.In certain applications, subjects may be tested before injury to establish their baseline performance (performance variability is expected based on the subject's fatigue and other conditions).

[0123] One advantage of the display screen 210, in which the majority of the screen is uniformly illuminated with a bright color such as white, is that the display screen 210 provides a relatively large diffuse light source within the interior chamber of the housing 262, illuminating the eye 101 so that the camera 220 can capture an image of the eye. This allows a large number of pixels on the display screen 210 to be illuminated at a relatively low level, so that sufficient illumination can be achieved even with a relatively low illumination level per pixel on the display screen 210, and the overall illumination can be sufficiently high. By preventing the light source from becoming a bright light source even when it is relatively small, glare for light-sensitive users can also be avoided.

[0124] In a specific use case of the eye-tracking device 200, the patient is asked to gaze at an object 305 and follow it with their eyes as it moves across the display screen 210. The camera 220 acquires information about the movement of the eyes 101 in response to this stimulus.

[0125] The eye-tracking device 200 can be used to track the movement of one eye of a patient at a time. The eye being evaluated can be positioned appropriately relative to the eye-tracking device 200, and when evaluating the other eye, the other eye can be positioned appropriately. In the case of the eye-tracking device 200 shown in Figures 6A to 6D, the aperture 270 is positioned toward one end of the housing 262. This allows the housing 262 to be positioned close to the patient's face and the eye 101 close to the aperture 270, and the rest of the housing extends laterally away from the patient's nose so that the nose does not obstruct the positioning of the housing. In this position, the display screen 210 may be positioned above the aperture 270, for example, just in front of the patient's forehead. When evaluating the other eye of the patient, the housing 262 can be inverted so that the other eye is close to the aperture 270 and the housing extends laterally away from the patient's opposite nose. In this position, the display screen 210 may be positioned below the aperture 270, for example, just in front of the patient's cheek. In fact, the eye tracking device 200 shown in Figures 6A-6D can be used in any orientation by rotating it around an axis passing through the center of the aperture 270.

[0126] In another form of this technology, for example, in the operation of device 200, also called the binocular version as shown in Figure 11, device 200 may be configured to present two eyes to the device at once, but eye tracking may only occur for one eye at a time. For example, the display screen 210 is initially configured to display an image for eye tracking on a portion of the screen visible to the first eye, and a corresponding camera captures image data of the first eye's movement. Subsequently, the display screen 210 is configured to display an image for eye tracking on a portion of the screen visible to the second eye, and each camera captures image data of the second eye's movement. When examining the eyes using this binocular version, the user has the advantage of not having to change the position of the device when switching from tracking one eye to tracking the other, compared to using the monocular version for each eye.

[0127] 4. Use of eye tracking information By using the eye-tracking device 200, information regarding changes in the image on the first display screen 210, such as the movement of the eyes 101 in response to the movement of an object 305, can be acquired. This information can be displayed on the second display screen 211, stored in the memory of the camera 210, transmitted to another device, or any combination of these options. If this information is transmitted to another device, such as a remote device, it may be stored on that other device and / or displayed on its display screen.

[0128] The specific form of this technology is not limited by the type of information regarding eye movement 101 obtained through the use of the eye tracking device 200.

[0129] Based on information about eye movements, one or more medical conditions may be examined, evaluated, and / or diagnosed. Specific forms of this technology are not limited by the nature of the evaluation or the medical condition(s) being evaluated.

[0130] 5. Other points to note Unless otherwise clearly indicated in the context, throughout the description and claims, the words “comprise,” “comprising,” and similar phrases shall be interpreted in a comprehensive sense, that is, “including, but not limited to,” and not in an exclusive or exhaustive sense.

[0131] All disclosures of applications, patents, and publications cited above and below are incorporated herein by reference, if any.

[0132] References to prior art in this specification do not constitute, nor should they be interpreted as, an acknowledgment or suggestion in any way that such prior art forms part of the common general knowledge of the art in any country of the world.

[0133] The aforementioned technology can also be broadly described as consisting of any or all of the parts, elements, or features described or shown in the specification of the aforementioned application, either individually or collectively, from any combination of two or more of the aforementioned parts, elements, or features.

[0134] Where, in the preceding description, integers or their equivalents are referred to as components for which integers are known, those integers are incorporated herein as if they were listed separately.

[0135] It should be noted that various changes and modifications to the currently preferred embodiments described herein will be obvious to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the art and without impairing the associated advantages. Therefore, such changes and modifications are intended to be included within this art. [Explanation of Symbols]

[0136] 101st 104 Muscles that control eye movement 106 Pupil 200 eye tracking devices 210 First display screen 211 Second display screen 212 Illusion 220 Cameras 225 lens 230 Reflector, reflector 232 Reflective surface 234 Opening 250 portable electronic devices 260 frames 262 Housing 264 Reflector holding structure 266 Display screen retention structure 267 Display Screen Slots 268 Camera holding structure 269 ​​camera slots 270 Aperture 271 Eyepiece Lens 272 Eyepiece Lens Frame 272 frames 274 Food 276 Opaque Cover 280 Front wall 281 Front wall gap, front wall gap 282 Back wall 283 Rear wall gap 284 First side wall 286 Second side wall 288 Upper wall 290 Lower wall 292 slot openings 303 Object 305 Movement path, object 350 light source 352 Diffuser 354 Lighting Unit

Claims

1. A device for tracking eye movements, wherein the device is Reflector, A display screen positioned relative to the reflector so that the eye can see the display screen reflected by the reflector when in use, A camera for photographing the eye when the eye is viewing the display screen, wherein the camera is positioned to photograph the eye through the reflector, A device that includes this.

2. The device according to claim 1, wherein the reflector includes an opening, and the camera is positioned to photograph the eye through the opening when in use.

3. The device according to claim 1, wherein the reflector is semi-transparent, the camera can photograph the eye through the reflector, and the device is configured such that the eye can view the display screen reflected by the reflector.

4. The device according to any one of claims 1 to 3, wherein the device is configured such that when the display screen is being viewed, the eye substantially fills the field of view of the camera.

5. The device according to any one of claims 1 to 4, wherein the device is configured such that the camera is positioned substantially in front of the eye during use.

6. The device according to any one of claims 1 to 4, wherein the device is configured such that the camera is positioned in front of and below the eye during use.

7. The device according to any one of claims 1 to 6, wherein the reflector has a reflective surface configured to reflect light from the display screen toward the eye, and the reflective surface is concave in at least one plane.

8. The device according to any one of claims 1 to 7, further comprising a frame configured to position the reflector, the display screen, and the camera relative to the eye during use.

9. The device according to claim 8, wherein the frame includes a housing for accommodating the reflector, the display screen, and the camera in a light-controlled environment, and the housing includes an opening that the eye is directed towards while the device is in use.

10. The device according to claim 9, wherein the housing substantially prevents ambient light from entering the light-controlled environment during use.

11. The device according to any one of claims 1 to 10, comprising one or more light sources.

12. The device according to claim 11, wherein the one or more light sources include the display screen.

13. The device according to claim 11 or 12, wherein the one or more light sources include one or more light sources separate from the display screen.

14. The device according to any one of claims 11 to 13, wherein the one or more light sources are diffuse light sources.

15. The device according to any one of claims 11 to 14, wherein the one or more light sources are positioned on one or more sides of the eye during use.

16. The device according to any one of claims 11 to 15, wherein the brightness of one or more light sources is adjustable.

17. The device according to any one of claims 11 to 16, wherein the frequency of light generated by the one or more light sources is adjustable.

18. The device according to any one of claims 1 to 17, wherein the display screen is included as part of a first portable electronic device.

19. The device according to any one of claims 1 to 18, wherein the camera is included as part of a second portable electronic device.

20. The device according to claim 19, wherein the display screen of the device for tracking eye movements is a first display screen, and the second portable electronic device includes a second display screen for displaying images captured by the camera.

21. The device according to claim 20, wherein the device is configured such that the camera of the second portable electronic device is within the light control environment and the second display screen of the second portable electronic device is outside the light control environment.

22. The device according to any one of claims 1 to 21, wherein the camera is configured to store and / or transmit images captured by the camera for viewing and / or analysis at a location away from the device, the eye, and / or the camera.

23. The reflector is a first reflector, and the device further includes a second reflector. The aforementioned eye is the user's first eye, and the user has a second eye, The display screen is positioned relative to the first and second reflectors such that, during use, the first eye views the display screen reflected by the first reflector, and the second eye views the display screen reflected by the second reflector. The device according to any one of claims 1 to 22, wherein the camera is the first camera, and the device further includes a second camera for photographing the second eye when the second eye is viewing the display screen, the second camera being arranged to photograph the second eye through the second reflector.

24. A frame suitable for use in devices for tracking eye movements, A reflector holding structure for positioning the reflector, A display screen holding structure for positioning the display screen relative to the reflector such that, when the reflector is placed within the reflector holding structure, the eye can see the display screen reflected by the reflector during use. A camera holding structure for positioning a camera for photographing the eye when the eye is viewing the display screen, A frame that includes this.

25. The frame according to claim 24, wherein the camera holding structure is configured to hold the camera, and the reflector holding structure is configured to hold the reflector such that, when in use, the camera photographs the eye through the reflector.

26. The frame according to claim 25, wherein the reflector includes an opening, and the camera is positioned to photograph the eye through the opening when in use.

27. The frame according to claim 25, wherein the reflector is semi-transparent, and the device is configured such that the camera can photograph the eye through the reflector, and the eye can view the display screen reflected by the reflector.

28. The frame according to any one of claims 24 to 27, wherein the frame is configured such that the eye substantially fills the field of view of the camera when viewing the display screen.

29. The frame according to any one of claims 24 to 28, wherein the frame includes a housing that houses the reflector, the display screen, and the camera in a light-controlled environment, and the housing includes an opening to which the eye faces during use of the device.

30. The frame according to claim 29, wherein the housing substantially prevents ambient light from entering the light-controlled environment from sources other than the opening.

31. The frame according to any one of claims 29 to 30, wherein the camera is included as part of a pre-facelift portable electronic device, the display screen of the device for tracking eye movements is a first display screen, the second portable electronic device includes a second display screen for displaying images captured by the camera, and the housing is configured such that the camera holding structure places the camera of the portable electronic device within the light-controlled environment, and the second display screen of the portable electronic device is outside the light-controlled environment.

32. The frame according to any one of claims 24 to 31, wherein the housing includes a first housing portion and a second housing portion, and the first housing portion and the second housing portion are configured to be assembled together to form the housing.

33. The frame according to claim 32, wherein the first housing portion includes the display screen holding structure and the camera holding structure, and the second housing portion includes an opening.

34. The reflector holding structure is a first reflector holding structure, the reflector is a first reflector, and the device further includes a second reflector holding structure for arranging the second reflector. The aforementioned eye is the user's first eye, and the user has a second eye, The display screen holding structure is configured such that, during use, the first eye views the display screen reflected by the first reflector, and the second eye views the display screen reflected by the second reflector, and the display screen is positioned relative to the first and second reflectors. The frame according to any one of claims 24 to 33, wherein the camera holding structure is the earlier first camera holding structure, and the device further includes a second camera holding structure for positioning a second camera for photographing the second eye when the second eye is viewing the display screen.

35. The frame according to claim 34, wherein the second camera holding structure is configured to position the second camera so as to photograph the second eye through the second reflector.

Images