Waveguide illumination for eye assessment

Abstract

Various implementations are based on the evaluation of eye characteristics using reflections (e.g., flash) generated by one or more light sources. In one embodiment, a device (e.g., HMD) has an optical device (e.g., a stack of one or more transparent elements) through which a user's physical environment is viewed. Light is emitted from a plurality of locations on or in the optics to generate a flash on the eye for eye assessment. One or more light sources may be located on the surrounding frame and may produce light directed into the one or more waveguides. The one or more waveguides may direct the light through the optics and then exit the optics at a particular exit location, e.g., via a prism, grating, or the like. The waveguides and associated elements are configured such that they are less likely to be noticed by a user in view of their small size, very close to the eye and / or material transparency.

Description

Technical Field

[0001] The present disclosure relates generally to electronic devices, and particularly to systems, methods, and devices for assessing gaze direction, eye orientation, and other eye characteristics of electronic device users. Background Art

[0002] Some existing eye assessment techniques analyze glints formed by reflecting light from a user's eye. On a head mounted device (HMD), such reflections / glints may be formed by projecting light toward the eye from a light source located on a side portion of the HMD (e.g., on a frame of the HMD) to avoid obstructing the user's field of view through a central portion of the HMD providing the optics or obstructing the central portion of the HMD. Generating light reflections from such side locations may be inefficient, inaccurate, or otherwise undesirable, particularly for HMDs having relatively large central portions (e.g., optics) and, therefore, side portions that may be relatively farther from the optical axis of the eye. Therefore, it may be desirable to provide a device that generates light directed toward the eye to generate glint by providing light from a more central location of the HMD (e.g., within the optics) without obstructing the user's field of view through a central portion of the HMD providing the optics or obstructing the central portion of the HMD. Summary of the invention

[0003] Various embodiments include devices, systems, and methods for evaluating eye characteristics (e.g., gaze direction, eye orientation, iris identifying the eye, etc.) based on reflections (e.g., flashes) generated using one or more light sources. Some embodiments provide a device (e.g., AR glasses or other HMD) having an optical device (e.g., a stack of one or more transparent elements) through which the user's physical environment is observed. Light is emitted from multiple exit positions on or in the optical device to illuminate the eye, thereby generating a flash for eye assessment. One or more light sources may be located on a peripheral frame of the device and generate light that is guided into one or more waveguides. One or more waveguides may guide light from one or more light sources through the optical device and then leave the optical device at different exit positions, for example, via a prism, a grating, etc. The waveguides and associated elements are configured so that, for example, based on their small size, close proximity to the eye, and / or the use of transparent materials, the user is unlikely to notice them.

[0004] Some implementations provide an electronic device having a frame that includes one or more light sources (e.g., light emitting diodes (LEDs), vertical cavity surface emitting lasers (VCSELs), etc.). The electronic device has an optics (e.g., a stack of glass, lenses, and other optical layers) coupled to the frame and including one or more waveguides positioned to direct light received from the one or more light sources of the frame to an exit location at a surface of the optics.

[0005] As used herein, the phrase "waveguide" refers to a light pipe, optical fiber, or other structure that guides waves (such as electromagnetic waves) by limiting transmission to one or more directions. A waveguide may be formed of a dielectric material having a high dielectric constant, and therefore a high refractive index, surrounded by a material having a lower dielectric constant. The structure of a waveguide may guide waves by total internal reflection. Waveguides include, but are not limited to, light pipes in the form of hollow tubes with a highly reflective interior surface.

[0006] The exemplary device also includes an image sensor and a processor. The processor can be configured to receive sensor data from the image sensor (e.g., sensor data corresponding to reflections of light emitted from the exit location and reflected from the eye) and evaluate eye characteristics based on the reflections.

[0007] Using a waveguide to generate light from multiple exit locations on the optics of the device to produce glint for eye assessment may provide a number of advantages. For example, doing so may enable light to be emitted from exit locations that are closer to the optical axis of the user's eye, which may be desirable in some implementations. The locations may be determined by running an optimization that generates some central exit locations and some edge exit locations. Light generated from locations relatively far from the optical axis of the eye may produce glint that is less desirable for eye assessment, for example, some glint may end up on the sclera instead of the pupil, or otherwise be inappropriate for eye assessment.

[0008] According to some specific implementations, a non-transitory computer-readable storage medium stores instructions, which are computer-executable to perform or cause the performance of any method described herein. According to some specific implementations, a device includes one or more processors, a non-transitory memory, and one or more programs, which are stored in the non-transitory memory and configured to be executed by the one or more processors, and the one or more programs include instructions for performing or causing the performance of any of the methods described herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order that the present disclosure may be understood by those skilled in the art, a more particular description will be given with reference to some exemplary implementations, some of which are illustrated in the accompanying drawings.

[0010] Figure 1 Exemplary electronic devices according to some implementations are illustrated.

[0011] Figure 2 Examples according to some specific implementations Figure 1 An exemplary use of one or more waveguides in an exemplary device.

[0012] Figure 3 Examples according to some specific implementations Figure 1 An exemplary use of one or more waveguides in an exemplary device.

[0013] Figure 4 The following examples are provided according to some specific implementations. Figure 3 Light guided within a waveguide and exiting the waveguide.

[0014] Figure 5 Examples according to some specific implementations Figure 1 An exemplary use of one or more waveguides in an exemplary device.

[0015] Figure 6 Exemplary layer stacks forming optical devices of exemplary apparatuses are illustrated according to some implementations.

[0016] FIG. 7A to FIG. 7B An exemplary process for forming at least a portion of an optic of an exemplary apparatus is illustrated according to some implementations.

[0017] Figure 8 Exemplary prismatic components according to some implementations are illustrated.

[0018] FIG. 9A to FIG. 9G An exemplary process for forming at least a portion of an optic of an exemplary apparatus is illustrated according to some implementations.

[0019] Fig.10 An exemplary process for forming at least a portion of an optic of an exemplary apparatus is illustrated according to some implementations.

[0020] Fig.11 Exemplary optical device positioning relative to an eye according to some specific implementations is illustrated.

[0021] Fig.12 Exemplary glints reflected from an eye model are illustrated.

[0022] Fig.13 is a flowchart representation of a method for evaluating eye characteristics of a user based on reflected light according to some specific implementations.

[0023] Fig.14 is a block diagram illustrating device components of an exemplary device according to some implementations.

[0024] As is common practice, the various features illustrated in the drawings may not be drawn to scale. Therefore, the sizes of the various features may be arbitrarily expanded or reduced for clarity. In addition, some of the drawings may not depict all of the components of a given system, method, or device. Finally, throughout the specification and drawings, similar reference numerals may be used to represent similar features. DETAILED DESCRIPTION

[0025] Many details are described in order to provide a thorough understanding of the example implementations shown in the accompanying drawings. However, the accompanying drawings only illustrate some example aspects of the present disclosure and should not be considered limiting. One of ordinary skill in the art will appreciate that other effective aspects or variations do not include all of the specific details described herein. In addition, well-known systems, methods, components, devices, and circuits are not described in detail in order to avoid obscuring more relevant aspects of the example implementations described herein.

[0026] Figure 1 The device 110 including a frame 212 that can be worn on a user's head is illustrated. The frame 212 includes extensions (e.g., arms) that are placed over the user's ears to hold the frame 212 in place on the user's head. The device 110 includes two optics 215a-215b for the user's right eye and left eye, respectively. Each of the optics 215a-215b can be configured as a stack of effectively transparent layers. Such layers can include: a bias (+ / -) layer for prescription lenses; a display waveguide layer for displaying XR content; an eye evaluation light layer that includes one or more waveguides for directing light from one or more exit locations within the optics 215a-215b toward the user's eyes to form a flash or otherwise for eye evaluation purposes, etc.

[0027] The device 110 enables a user to observe at least a portion of the surrounding physical environment by looking through the optical devices 215a-215b. The device 110 may be an HMD that includes the optical devices 215a-215b through which a portion of the surrounding physical environment is observed and on which additional (e.g., virtual) content may be displayed. The device 110 may take the form of "XR glasses." In these examples, the device 110 enables a user to observe the surrounding physical environment and / or virtual content via the optical devices 215a-215b while the device 110 obtains image data, motion data, and / or physiological data (e.g., pupil data, facial feature data, etc.) from the user via one or more sensors (e.g., detectors 220a, 220b). The one or more detectors 220a-220b may include one or more image sensors (e.g., IR cameras) that capture images or otherwise provide captured data to detect reflected light (e.g., flashes) from the user's eyes for eye assessment purposes.

[0028] In some implementations, the device 110 also includes one or more controllers 250a-250b, each controller including a processor and / or a power source that controls light emitted from one or more light sources to be directed toward the user's eyes to form reflections (e.g., flashes) for eye assessment. In some implementations, each of the controllers 250a-250b is a microcontroller that can control the process described herein for assessing characteristics of the corresponding eye (e.g., gaze direction, eye orientation, identifying the iris of the eye) based on sensor data obtained from each of the detectors 220a-220b.

[0029] In some specific implementations, such as Figure 1 , device 110 is a wearable device, such as an HMD. In other implementations, device 110 is a handheld electronic device (e.g., a smartphone or tablet). In some implementations, device 110 is a laptop or desktop computer. In some implementations, device 110 has a trackpad, and in some implementations, device 110 has a touch-sensitive display (also referred to as a "touch screen" or "touch screen display").

[0030] In some implementations, the device 110 includes an eye assessment system for assessing the user's eyes (e.g., detecting eye positioning and eye movement). For example, the eye assessment system may include one or more light sources (e.g., IR / NIR light sources) and one or more cameras (e.g., IR / NIR cameras) sensitive to wavelengths emitted by the one or more light sources. In some implementations, images captured by the eye assessment system may be analyzed to detect positioning and movement of the user's eyes, or to detect other information about the eyes such as color, shape, state (e.g., fully open, squinting, etc.), pupil dilation, or pupil diameter. In addition, the gaze point may be estimated based on the eye assessment to enable gaze-based interaction with content displayed at the optics 215a-215b of the device 110.

[0031] According to some implementations, an electronic device (e.g., device 110) described herein can generate an extended reality (XR) environment and present it to a user, and can evaluate eye characteristics (e.g., gaze direction) relative to such an XR environment.

[0032] Although this example and other examples discussed herein illustrate a single device 110, the techniques disclosed herein are applicable to multiple devices. For example, the functionality of device 110 may be performed by multiple devices.

[0033] Figure 2 An example configuration is illustrated for lens 215b and surrounding frame portion 212b of device 110. Lens 215a (and frame portion 212a) may have a similar configuration. Figure 2 Components of an eye assessment system of device 110 are illustrated. In this example, these components include one or more light sources 252a-252c, one or more waveguides 245a-245g, a detector 220b, and a controller 250b. Controller 250b can control one or more light sources 252a-252c and provide power to the one or more light sources. The one or more light sources can be vertical cavity surface emitting lasers (VCSELs), light emitting diodes (LEDs), or any other type of light source. Specific implementations using VCSELS in conjunction with waveguides can provide advantages, such as enabling efficient provision of uniform illumination. VCSELs can be power efficient, and the use of waveguides can help reduce or remove coherence, which can otherwise cause spots to appear on the sensor image of the eye. Coupling VCSELs into waveguides can also be relatively efficient. One or more light sources can produce light with specific characteristics, such as producing IR or NIR light.

[0034] One or more waveguides 245a-245g are positioned within the optical device 215b to direct light from the one or more light sources 252a-252c to the exit locations 240a-240g. The one or more waveguides 245a-245g can be configured to have a sufficiently small size / diameter and / or can be made at least partially of one or more transparent materials so as to be undetectable by the human eye of a user wearing the device 110. The one or more waveguides 245a-245g can be configured to be effectively transparent to a user when the device 110 is worn and content is viewed through the optical device 215b.

[0035] The exit locations 240a-240g may be locations where one or more waveguides 245a-245g direct light from one or more light sources 252a-252c. The exit locations 240a-240g may be locations where an exit component (e.g., a prism, a grating, etc.) is positioned to direct light from within the one or more waveguides 245a-245g outward (e.g., away from the optical device 215b and toward the user's eyes) when the user wears the device 110.

[0036] Figure 3 Another example configuration of lens 215b and surrounding frame portion 212b for device 110 is illustrated. Lens 215a (and frame portion 212a) may have a similar configuration. In this example, the eye assessment component includes one or more light sources 352a-352b, one or more waveguides 345a-345e, detector 220b and controller 250b. Controller 250b may control one or more light sources 352a-352b and provide power to the one or more light sources via conductors. One or more light sources may be vertical cavity surface emitting lasers (VCSELs), light emitting diodes, or any other type of light source. One or more light sources may generate light with specific characteristics, such as generating IR or NIR light.

[0037] One or more waveguides 345a-345e are positioned within the optics 215b to direct light from the one or more light sources 352a-b to a plurality of exit locations (e.g., exit location 340) along the path 335. The one or more waveguides 345a-345e may be configured to have a sufficiently small size / diameter and / or may be made of one or more transparent materials so as to be undetectable by the human eye of a user wearing the device 110 and thus be perceived as transparent when viewing content through the optics 215b.

[0038] The exit location may be a location where one or more waveguides 345a-345e direct light from one or more light sources 352a-352c. The exit location (e.g., exit location 340) forms a circular path 335 on the optical device 215b and may be a location where an exit component (e.g., a prism, a grating, etc.) is positioned to direct light from the one or more waveguides 345a-345e outward (e.g., away from the optical device 215b and toward the user's eyes) when the user wears the device 110.

[0039] Figure 4 Light 410 is illustrated being guided within and exiting a waveguide 445. In this example, light 410 (which may originate from a source such as Figure 3 The light source 352a of light source 352a) travels within the waveguide 445 and is then redirected by the prism 440 out of the waveguide 445 (and corresponding optical device 215b) toward the user's eye.

[0040] Figure 5 Another example configuration for the lens 215b and surrounding frame portion 212b of the device 110 is illustrated. The lens 215a (and frame portion 212a) may have a similar configuration. In this example, the eye assessment component includes a light source 550, a waveguide 545, a detector 220b, and a controller 250b. The controller 250b may control the light source 552 and provide power to the light source. The light source may be a vertical cavity surface emitting laser (VCSEL), a light emitting diode (LED), or any other type of light source. The light source may generate light with specific characteristics, such as generating IR or NIR light.

[0041] Waveguide 545 is positioned within optics 215b to direct light from light source 552 to exit locations 540a-540f. Waveguide 545 may be configured to have a sufficiently small size / diameter and / or may be made of one or more transparent materials so as to be undetectable to the human eye of a user wearing device 110 and therefore be perceived as transparent when viewing content through optics 215b.

[0042] The exit locations 540a-540f may be locations where the waveguide 545 directs light from the light source 552. In this example, there are multiple locations along a single waveguide 545. The exit locations 540a-540f form an approximately circular pattern on the optics 215b and may be locations where exit components (e.g., prisms, gratings, etc.) are positioned to direct light from the waveguide 545 outward (e.g., away from the optics 215b and toward the user's eyes when the user wears the device 110).

[0043] Figure 6An exemplary stack 600 of the optics of an exemplary device is illustrated relative to a frame 605 and a user's eye 690. The stack 600 includes a tinted cover glass layer 610, a tinted layer 630 (e.g., having an organic electrochromic glass and a controller / controller connection 620), a cover glass layer 650, an eye evaluation light layer 655, and a display waveguide layer 680. For example, a bias layer (not shown) may additionally be included below the display waveguide layer 680.

[0044] The eye evaluation light layer 655 includes a waveguide formed by a channel of high refractive index material 656 surrounded by low refractive index material 660, and an air gap 670. The low refractive index material 660 can be selected to reduce the visibility of the waveguide. This selection of low refractive index material 660 can take into account the dependence of refractive index on wavelength. The selection can be based on criteria requiring low contrast in the visible light range (to reduce visibility) and higher contrast in NIR wavelengths (to improve guidance with higher angular content).

[0045] Light from a light source 675 (e.g., from a VCSEL array) is directed through a waveguide (e.g., through a channel formed by a high index material 656 surrounded by a low index material 660) and exits the optical device at an exit location 665 (e.g., a prism or grating at that location). The light source 675 can reside in and / or adjacent to a frame portion of the device and can be driven by a driver (e.g., a VCSEL driver). In some implementations, the eye evaluation layer 655 is relatively thin (e.g., 2 to 20 microns).

[0046] like Figure 6As illustrated in , the eye assessment component may provide multiple transparent illumination sources on the optical device of the electronic device by means of a waveguide (such as a light pipe). Such a waveguide can be formed using conventional wafer patterning techniques or other techniques. In some specific implementations, the light source 675 (e.g., VCSEL) is configured to generate light in the range of the upper limit of the visible spectrum (e.g., 700nm) to the upper limit of the optical range capability of the sensor (e.g., 1500nm). In some specific implementations, the light source 675 (e.g., VCSEL) is configured to generate light in the range of 800nm ​​to 1100nm. In some specific implementations, the light source 675 (e.g., VCSEL) is configured to generate light in the range of 900nm to 1000nm, for example, generating light of approximately 940nm. The light source 675 (e.g., 940nm VCSEL) can inject light from the edge of the optical device into the waveguide (e.g., a channel formed by the high refractive index material 656), for example, the light source can be positioned on the frame instead of in the optical device itself. In some implementations, some or all of the light sources 675 are positioned within the optical device. In such cases, the light sources 675 are preferably small and / or transparent, or otherwise configured or positioned to avoid obscuring the field of view provided through the optical device.

[0047] In some implementations, the eye evaluation light layer 655 is configured with multiple exit components (e.g., prisms, gratings, etc.) that are configured to generate light from multiple exit locations on the optical device toward the user's eyes to produce reflections (e.g., flashes) from the eyes that can be used for eye evaluation. In some implementations, the exit components (e.g., prisms) are coated with a wavelength-specific (e.g., 940nm) or wavelength range-specific reflective coating that is transparent to human vision. The prism / reflective surface can be relatively small (e.g., less than 75μm×75μm). Such a prism can be fixed by gluing in place (e.g., by gluing on one edge). The low refractive index material 660 can be transparent and is configured to cover the waveguide structure while reducing reflections.

[0048] In some implementations, nanoimprint technology is used to form the waveguide. In some implementations, a grating (or other exit component) is used to direct light out of the optics at a specific location and toward the user's eye. In some implementations, a negative mold of the light pipe is etched in silicon with sub-micron precision. A high refractive index transparent material is applied to the glass and formed through the mold, and a low refractive index transparent material is added to cover the structure to reduce reflections.

[0049] Fig. 7AAn exemplary process for forming at least a portion of an optical device of an exemplary device is illustrated. In this example, at step 702, a transparent substrate (e.g., glass, polycarbonate, cycloolefin polymer (COP), or other transparent polymer material) 710 is formed. At step 704, a high refractive index polymer 720, such as SU-8 (~1.58@940nm), is added, for example, by photolithography or laser. At step 706, microprisms 730 with coated facets (e.g., for the 940nm range) are added. At step 708, a filling structure of a low refractive index material 740 is added. In an alternative implementation, an air gap is used instead of a low refractive index material 740. However, the contrast may be significant enough to make the edge visible. The low refractive index material 740 can provide a smaller contrast and therefore provide a smaller visibility possibility.

[0050] Figure 8 An exemplary prism 720 is illustrated. In one example, the prism 720 is transparent except for a portion 810 having a reflective coating (e.g., gold). In another example, the prism 720 is completely transparent and the portion 810 has zero reflectivity in the visible range (e.g., 400nm-700nm), but is reflective in the range of light from the light source (e.g., 940nm). In some implementations, a reflector material containing a metal is used (e.g., copper plated, gold plated material, etc.). The reflector material can be grown / applied directly on the substrate.

[0051] Figure 7B An exemplary process for forming at least a portion of an optical device of an exemplary device is illustrated. In this example, at step 702b, a transparent substrate (e.g., glass, polycarbonate, cyclic olefin polymer (COP), or other transparent polymer material) 710b is formed. At step 704b, a high refractive index polymer 720b, such as SU-8 (~1.58 @ 940nm) is added, such as by photolithography or laser. At step 706, microprisms 730b with coated facets (e.g., for the 940nm range) are added. The microprisms 730b are formed with Fig. 7A The microprisms 730 are oriented in different exemplary orientations. At step 708b, a filling structure of low refractive index material 740 is added. In an alternative implementation, air gaps are used instead of low refractive index material 740. However, the contrast may be significant enough to make the edge visible. Low refractive index material 740 can provide less contrast and therefore less visibility potential.

[0052] Fig. 9AAn exemplary process for forming at least a portion of an optical device of an exemplary device is illustrated. In this example, at step 902, a transparent substrate (e.g., glass, polycarbonate, cycloolefin polymer (COP), or other transparent polymer material) 910 is formed. At step 904, a high refractive index polymer 920, such as SU-8 (~1.58@940nm), is added, for example, by photolithography or laser. At step 906, shapes 930a-930b are formed from a low refractive index material (e.g., a polymer) using nanoimprinting. At step 908, an exit component 935 is formed on shape 930b using mirror coating and patterning techniques. At step 909, a low refractive index material coating is added, which is combined with shapes 930a-930b to form a low refractive index material region 950. The exit component 935 is embedded in the low refractive index material 950 in this manner.

[0053] Fig. 9B An exemplary process for forming at least a portion of an optical device of an exemplary device is illustrated. In this example, at step 902b, a transparent substrate (e.g., glass, polycarbonate, cycloolefin polymer (COP) or other transparent polymer material) 910b is formed. At step 904b, a high refractive index polymer 920b, such as SU-8 (~1.58@940nm), is added, for example, by photolithography or laser. At step 906b, shapes 930c-930d are formed from low refractive index materials (e.g., polymers) using nanoimprinting. At step 908b, an exit component 935b is formed on shape 930c using mirror coating and patterning techniques. At step 909b, a low refractive index material coating is added, which is combined with shapes 930c-930d to form a low refractive index material region 950b. The exit component 935b is embedded in the low refractive index material 950b in this way.

[0054] Fig. 9C An exemplary process for forming at least a portion of an optical device of an exemplary device is illustrated. In this example, at step 962, a transparent substrate (e.g., glass, polycarbonate, cycloolefin polymer (COP), or other transparent polymer material) 970 is formed. At step 964, the or other transparent substrate 970 is patterned, for example, by photolithography or laser. At step 966, additional etching is optionally performed to place prisms. At step 968, the etched grooves / channels are filled with a high refractive index material 972, for example, via photolithography or overflow and polishing techniques. At step 969, a mirror 976 is attached and a portion 974 is filled with a low refractive index material (such as glass).

[0055] Fig.9D Illustrated with Fig. 9CThe process is similar to the exemplary process for forming at least a portion of the optics of the exemplary device. However, at step 929, mirror 976b is attached and portion 974 is filled with a low refractive index material (such as glass). Fig.9D The mirror 976b has Fig. 9C Different positioning and orientation of mirrors.

[0056] Fig.9E An exemplary process for forming at least a portion of an optical device of an exemplary device is illustrated. In this example, at step 982, a transparent substrate (e.g., glass, polycarbonate, cycloolefin polymer (COP), or other transparent polymer material) 990 is formed. At step 984, the glass or other transparent substrate 990 is patterned, for example by photolithography or laser, to form a rounded edge profile. At step 986, any etched grooves / channels are filled with a high refractive index material 992, for example via photolithography or overflow and polishing techniques. At step 989, a portion 994 is filled with a low refractive index material (such as glass).

[0057] In various embodiments, light is directed across the clear aperture to a location and then coupled to the user's eyes by diffuse scattering from the waveguide tip (e.g., coated with a high reflectivity coating). Due to the small (e.g., micrometer-scale) feature size and its transparency, this approach can provide minimal visibility of the lighting system. The diffusely scattered light can provide a near-Lambertian illumination source with a wide angle, which can allow a large area of ​​the user's face to be illuminated from a very close distance. The shape of the tip can be configured to improve lighting efficiency and reduce back reflections to the light source. In some specific implementations, these components are configured to generate light in a direction away from the waveguide (e.g., vertically) while also diffusing the light, similar to an LED. In some specific implementations, a reflector material containing metal is used (e.g., copper-plated, gold-plated materials, etc.). The reflector material can be directly grown / applied on a substrate.

[0058] Fig.9F An exemplary process for forming at least a portion of an optical device of an exemplary apparatus is illustrated. In this example, at step 1902, a transparent substrate (e.g., glass, a polycarbonate substrate, a cyclic olefin polymer (COP), or other transparent polymeric material) 1910 and a waveguide 1912 (e.g., a transparent polymer) having a tip 1914 are formed. Figure 9G An isometric view of an exemplary geometry of a waveguide 1912 having a tip 1914 is illustrated. Fig.9F In step 1904, the waveguide 1912 is coated with a diffuser layer 1916. At step 1906, a low refractive index (LRI) cladding layer is added. At step 1908, a light source 1918 is coupled.

[0059] Fig.10An exemplary process for forming at least a portion of an optical device of an exemplary apparatus is illustrated. In this example, at step 1002, a transparent substrate (e.g., glass, polycarbonate, cyclic olefin polymer (COP), or other transparent polymer material) 1010 is formed. At step 1004, a high refractive index polymer 1020, such as SU-8 (~158@940nm), including grating couplers 1030a-1030b, is added, for example, by photolithography or laser. At step 1006, encapsulation with a low refractive index material 1040 is optionally performed. At step 1010, partial encapsulation can be provided if desired.

[0060] Fig.11 An exemplary optics 1100 is illustrated positioned relative to an eye 1120. In this example, light is directed through the optics 1100 to exit at an exit location (e.g., exit location 1110) toward the eye 1120. The light reflects from the eye 1120 to form a flash of light in the image data captured by the image sensor 1115. Fig.12 An exemplary glint (e.g., glint 1210) reflected from an eye model is illustrated. The glint may appear as a bright spot or otherwise distinguishable area in an image captured by an image sensor, and the relative positioning may be used to determine the position and / or orientation of the eye.

[0061] Fig.13 1 is a flowchart illustrating an exemplary method 1300. In some implementations, a device (e.g., device 110) performs method 1300 to evaluate eye characteristics. In some implementations, method 1300 is performed on a mobile device, a desktop computer, a laptop computer, an HMD, or a server device. Method 1300 may be performed by a processing logic component (including hardware, firmware, software, or a combination thereof). In some implementations, method 1300 is performed on a processor that executes code stored in a non-transitory computer-readable medium (e.g., a memory). In some implementations, method 1300 is performed in a combination of one or more devices as described herein. For example, sensor data from multiple light sensors may be acquired at an HMD (e.g., device 110), but processing of the data (e.g., evaluating eye characteristics) may be performed at a separate device (e.g., a mobile device).

[0062] At block 1302, method 1300 directs light through a waveguide to an exit location on an optical device of a device. The light generates a flash by generating light reflected from a portion of an eye (e.g., specular reflection). In some implementations, the flash can be a specular reflection flash. In some implementations, the light is IR light. In some implementations, the light source is a VCSEL or an LED.

[0063] At block 1304, method 1300 receives sensor data from an image sensor corresponding to a plurality of reflections of light reflected from an eye. For example, the sensor (e.g., detectors 220a-220b) may be an IR image sensor / detector that receives reflections of light from an eye (e.g., a flash).

[0064] In some implementations, method 1300 determines the location of the flash based on the reflected light received at the sensor. For example, determining the location of the flash may include determining the centroid of the received light. In some implementations, multiple flashes may be generated and located by the sensor (e.g., detector 220).

[0065] At block 1306, method 1300 assesses characteristics of the eye based on the sensor data. In some implementations, assessing eye characteristics of the eye can be based on the determined glint position. Eye characteristics can include gaze direction, eye orientation, iris identification of the eye, and the like. For example, if the electronic device is an HMD, an eye assessment system for the HMD can track the user's gaze direction, eye orientation, iris identification, and the like.

[0066] In some implementations, determining the orientation of the eye is based on identifying a pattern of flashes / light reflections in an image. In one example, the gaze direction can be determined using sensor data to identify two points on the eye, e.g., the center of the cornea and the center of the eyeball. In another example, the gaze direction can be determined using sensor data (e.g., a pattern of flashes) to directly predict the gaze direction. For example, a machine learning model can be trained to directly predict the gaze direction based on sensor data.

[0067] In some specific implementations, for iris recognition, the user may be uniquely identified based on a registration process or a previous iris assessment. Method 1300 may include evaluating characteristics from the eye by performing an identification or authentication process. Such a process may include identifying the iris of the eye. For example, matching the pattern of flashes / light reflections in the image with a unique pattern associated with the user. In some embodiments, iris recognition technology (e.g., matching patterns) can be used for anti-spoofing. For example, there may be multiple registration patterns that can be changed and can be used to authenticate the user's iris against a pre-registered biometric template, and confirm that the user is the correct person, the real person, and is being authenticated in real time. Iris recognition can be used as a primary authentication mode or as part of a multi-factor or step-by-step authentication. Matching patterns may be stored in a database located on an HMD (e.g., device 110), another device communicatively coupled to the HMD (e.g., a mobile device that electronically communicates with the HMD), an external device or server (e.g., connected via a network), or a combination of these or other devices.

[0068] In some implementations, assessing the characteristic of the eye includes determining the positions of multiple parts of the eye based on determining the positions of multiple flashes. In some implementations, assessing the characteristic of the eye is based on sensor data from a single sensor. In some implementations, the sensor (e.g., detector 220) includes an image sensor, and receiving the reflected light includes receiving the reflected light based on image data from the sensor.

[0069] In some implementations, an electronic device includes: a frame including one or more light sources (e.g., LEDs, VCSELs, etc.); and an optical device (e.g., glass, lenses, optical component stacks, etc.) coupled to the frame and including one or more waveguides positioned to guide light received from one or more light sources of the frame to an exit position at a surface of the optical device. The waveguides may be configured to be transparent. The optical device may include multiple layers. In one example, the layers include: a first layer including a waveguide to guide light reflected from an eye; and a second layer including a second waveguide positioned to display augmented reality content. The first layer may include: a first portion including a first transparent material or an air gap having a first transparency index; and a second portion including a second transparent material having a second transparency index greater than the first transparency index. The optical device may include a cover glass layer and / or a tinted layer.

[0070] The optical device may include one or more exit components, such as a prism, a grating, and the like. In one example, the optical device further includes a prism including a reflective surface that guides light to leave the optical device at an exit position. In one example, the prism or reflective surface is coated with a coating that is transparent to at least some light in the visible light range and reflective to at least some light outside the visible light range generated by one or more light sources. Such a reflective surface may be relatively small so that it is not visible to the naked eye. Each reflective surface may be smaller than a threshold associated with naked eye visibility, for example, each reflective surface is less than 75 μm×75 μm, each reflective surface is less than 100 μm×100 μm, each reflective surface is less than 125 μm×125 μm, and the like. In some specific implementations, a reflector material containing metal is used (e.g., copper-plated, gold-plated materials, etc.). The reflector material may be grown / applied directly on a substrate.

[0071] One or more waveguides may be formed by wafer patterning techniques or nanoimprinting techniques. Each of the one or more waveguides may include: a polymer patterned by photolithography or laser; and a microprism including at least one facet coated to reflect light for producing eye reflection using a specific wavelength or wavelength range (e.g., between 900nm and 1000nm). Each of the one or more waveguides may also have a filling structure having a lower refractive index than the polymer. In some implementations, each waveguide includes: a polymer patterned by photolithography or laser; and a reflective shape embedded in a filling structure having a lower refractive index than the polymer.

[0072] The electronic device also includes an image sensor (e.g., an IR image sensor / detector) and a processor configured to: receive sensor data from the image sensor corresponding to reflections of light emitted from an exit location and reflected from the eye; and evaluate eye characteristics based on the reflections.

[0073] The electronic device may also include a second waveguide positioned to display augmented reality (AR) or other extended reality (XR) content.

[0074] The electronic device may have exit locations that are spaced apart from each other relative to the surface of the optical device to emit light toward the eye from multiple directions. In some implementations, each exit location is approximately equidistant from an adjacent light source. For example, the spatial arrangement of multiple exit locations may form a uniformly spaced grid 3×3, 4×4, etc. In some implementations, each exit location is spaced apart from each adjacent exit location based on a minimum distance constraint.

[0075] In some implementations, the exit positions are divided into subgroups, and each subgroup includes two or more exit positions. In some implementations, the subgroups of exit positions are dispersed throughout the optical device. For example, the exit positions can be grouped in groups of three exit positions, and each group can be spread out in any spatial arrangement (e.g., an equidistant grid, an ellipse, a box, etc.).

[0076] In some implementations, the spatial arrangement of the exit positions is based on a geometric shape. In some implementations, the geometric shape includes shapes such as a parabola, an ellipse, a hyperbola, a cycloid, etc. In some implementations, the geometric shape is based on a transcendental curve or an algebraic curve.

[0077] Fig.141 is a block diagram of an example device 1400. Device 1400 illustrates an example device configuration for device 110. While certain specific features are illustrated, those skilled in the art will appreciate from this disclosure that various other features are not illustrated for the sake of brevity and so as not to obscure more relevant aspects of the implementations disclosed herein. To this end, as a non-limiting example, in some embodiments, the device 1400 includes one or more processing units 1402 (e.g., microprocessors, ASICs, FPGAs, GPUs, CPUs, processing cores, etc.), one or more input / output (I / O) devices and sensors 1406, one or more communication interfaces 1408 (e.g., USB, FIREWIRE, THUNDERBOLT, IEEE 802.3x, IEEE 802.11x, IEEE802.16x, GSM, CDMA, TDMA, GPS, IR, BLUETOOTH, ZIGBEE, SPI, I2C, and / or similar types of interfaces), one or more programming (e.g., I / O) interfaces 1410, one or more displays 1412, one or more internal-facing and / or external-facing image sensor systems 1414, memory 1420, and one or more communication buses 1404 for interconnecting these and various other components.

[0078] In some implementations, the one or more communication buses 1404 include circuits that interconnect system components and control communications between system components. In some implementations, the one or more I / O devices and sensors 1406 include at least one of the following: an inertial measurement unit (IMU), an accelerometer, a magnetometer, a gyroscope, a thermometer, one or more physiological sensors (e.g., a blood pressure monitor, a heart rate monitor, a blood oxygen sensor, a blood glucose sensor, etc.), one or more microphones, one or more speakers, a haptic engine, one or more depth sensors (e.g., structured light, time of flight, etc.), etc.

[0079] In some implementations, one or more displays 1412 are configured to present a view of a physical or graphical environment to a user. In some implementations, one or more displays 1412 correspond to holographic, digital light processing (DLP), liquid crystal display (LCD), liquid crystal on silicon (LCoS), organic light emitting field effect transistor (OLET), organic light emitting diode (OLED), surface conduction electron emitter display (SED), field emission display (FED), quantum dot light emitting diode (QD-LED), microelectromechanical system (MEMS), and / or similar display types. In some implementations, one or more displays 1412 correspond to diffraction, reflection, polarization, holographic, etc. waveguide displays. In one example, device 1400 includes a single display. In another example, device 1400 includes a display for each eye of the user (e.g., device 210).

[0080] In some implementations, the one or more image sensor systems 1414 are configured to obtain image data corresponding to at least a portion of the physical environment 5. For example, the one or more image sensor systems 1414 include one or more RGB cameras (e.g., with complementary metal oxide semiconductor (CMOS) image sensors or charge coupled device (CCD) image sensors), monochrome cameras, IR cameras, depth cameras, event-based cameras, etc. In various implementations, the one or more image sensor systems 1414 also include an illumination source that emits light, such as a flash. In various implementations, the one or more image sensor systems 1414 also include an on-camera image signal processor (ISP) that is configured to perform multiple processing operations on the image data.

[0081] Memory 1420 includes high-speed random access memory, such as DRAM, SRAM, DDR RAM or other random access solid-state memory devices. In some specific implementations, memory 1420 includes non-volatile memory, such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices or other non-volatile solid-state storage devices. Memory 1420 optionally includes one or more storage devices remotely located from one or more processing units 1402. Memory 1420 includes non-transitory computer-readable storage media.

[0082] In some implementations, the memory 1420 or a non-transitory computer-readable storage medium of the memory 1420 stores an optional operating system 1430 and one or more instruction sets 1440. The operating system 1430 includes processes for handling various basic system services and for performing hardware-related tasks. In some implementations, the instruction set 1440 includes executable software defined by binary information stored in the form of electrical charge. In some implementations, the instruction set 1440 is software that can be executed by one or more processing units 1402 to implement one or more of the techniques described herein.

[0083] The instruction set 1440 includes a flash analysis instruction set 1442, a physiological tracking instruction set 1444, and a light driver instruction set 1446. The instruction set 1440 may be embodied as a single software executable file or multiple software executable files. In some implementations, the flash analysis instruction set 1442 may be executed by the processing unit 1402 to determine the location of the flash based on the reflected light received at the sensor. In some implementations, the physiological tracking (e.g., eye gaze characteristics) instruction set 1444 may be executed by the processing unit 1402 to track and evaluate eye characteristics or other physiological attributes based on the determined flash location (e.g., according to the flash analysis instruction set 1442) using one or more of the techniques discussed herein or as otherwise may be appropriate. In some implementations, the light driver instruction set 1446 may be executed by the processing unit 1402 to activate and control the light source using one or more of the techniques discussed herein or as otherwise may be appropriate.

[0084] Although the instruction set 1440 is shown as residing on a single device, it should be understood that in other implementations, any combination of elements may be located in separate computing devices. Fig.14 The instructions set is intended to be more of a functional description of the various features present in a particular implementation rather than a schematic representation of the architecture of the implementations described herein. As will be appreciated by one of ordinary skill in the art, items shown separately may be combined, and some items may be separated. The actual number of instruction sets and how the features are distributed among them will vary depending on the implementation and may depend in part on the specific combination of hardware, software, and / or firmware selected for a particular implementation.

[0085] It should be understood that the specific implementations described above are cited by way of example, and the present disclosure is not limited to what has been particularly shown and described above. On the contrary, the scope includes both combinations and sub-combinations of the various features described above, as well as variations and modifications of the various features that would occur to a person skilled in the art upon reading the foregoing description and that are not disclosed in the prior art.

[0086] As described above, one aspect of the present technology is to collect and use physiological data to improve the user's electronic device experience in interacting with electronic content. The present disclosure contemplates that, in some cases, the collected data may include personal information data that uniquely identifies a particular person or can be used to identify the interests, characteristics, or tendencies of a particular person. Such personal information data may include physiological data, demographic data, location-based data, telephone numbers, email addresses, home addresses, device characteristics of personal devices, or any other personal information.

[0087] The present disclosure recognizes that the use of such personal information data in the present invention technology can be used to benefit users. For example, personal information data can be used to improve the interaction and control capabilities of electronic devices. Therefore, the use of such personal information data enables planned control of electronic devices. In addition, the present disclosure also anticipates other uses of personal information data that benefit users.

[0088] The disclosure also contemplates that entities responsible for the collection, analysis, disclosure, transmission, storage or other purposes of such personal information and / or physiological data will comply with established privacy policies and / or privacy practices. Specifically, such entities should implement and adhere to the use of privacy policies and measures that are recognized as meeting or exceeding the industry or government requirements for the privacy and security of maintaining personal information data. For example, personal information from users should be collected for the legal and reasonable purposes of entities, and not shared or sold outside these legal purposes. In addition, such collection should only be carried out after receiving the informed consent of the user. Additionally, such entities should take any required steps to safeguard and protect access to such personal information data, and ensure that other people who can access personal information data comply with their privacy policies and procedures. In addition, such entities can subject themselves to third-party assessments to prove that they comply with widely accepted privacy policies and practices.

[0089] Regardless of the foregoing, the present disclosure also contemplates implementations in which users selectively block the use or access of personal information data. That is, the present disclosure contemplates that hardware elements or software elements may be provided to prevent or block access to such personal information data. For example, with respect to a content delivery service customized for a user, the technology of the present invention may be configured to allow a user to choose to "opt in" or "opt out" of participating in the collection of personal information data during registration for the service. In another example, a user may choose not to provide personal information data for a target content delivery service. In yet another example, a user may choose not to provide personal information but allow anonymous information to be transmitted for use in improving the functionality of the device.

[0090] Thus, while the present disclosure broadly covers the use of personal information data to implement one or more of the various disclosed embodiments, the present disclosure also contemplates that various embodiments may also be implemented without access to such personal information data. That is, various embodiments of the present technology will not fail to function properly due to the lack of all or a portion of such personal information data. For example, content may be selected and delivered to a user by inferring preferences or settings based on non-personal information data or an absolute minimum amount of personal information, such as content requested by a device associated with the user, other non-personal information available to a content delivery service, or publicly available information.

[0091] In some embodiments, data is stored using a public / private key system that only allows the owner of the data to decrypt the stored data. In some other implementations, data can be stored anonymously (e.g., without identification and / or without personal information about the user, such as legal name, username, time and location data, etc.). In this way, other users, hackers, or third parties cannot determine the identity of the user associated with the stored data. In some implementations, a user can access his or her stored data from a user device that is different from the user device used to upload the stored data. In these cases, the user may need to provide login credentials to access the data stored therein.

[0092] Numerous specific details are set forth herein to provide a comprehensive understanding of the claimed subject matter. However, one skilled in the art will appreciate that the claimed subject matter may be practiced without these specific details. In other instances, methods, devices, or systems known to those of ordinary skill are not described in detail so as not to obscure the claimed subject matter.

[0093] Unless otherwise specifically noted, it should be understood that throughout this specification, discussions utilizing terms such as "process," "compute," "calculate," "determine," and "identify" refer to the actions or processes of a computing device, such as one or more computers or similar electronic computing devices, that manipulate or transform data represented as physical electronic or magnetic quantities within a memory, register, or other information storage device, transmission device, or display device of a computing platform.

[0094] The one or more systems discussed herein are not limited to any particular hardware architecture or configuration. A computing device may include any suitable arrangement of components that provide results conditioned on one or more inputs. Suitable computing devices include multi-purpose microprocessor-based computer systems that access stored software that programs or configures the computing system from a general-purpose computing device to a dedicated computing device that implements one or more specific implementations of the subject matter of the present invention. Any suitable programming, scripting, or other type of language or combination of languages ​​may be used to implement the teachings contained herein in software for programming or configuring a computing device.

[0095] The specific implementation of the method disclosed herein can be performed in the operation of such a computing device. The order of the boxes presented in the above examples can be changed, for example, the boxes can be reordered, combined or divided into sub-boxes. Some boxes or processes can be executed in parallel.

[0096] The use of "suitable for" or "configured to" herein is meant to be open and inclusive language that does not exclude devices that are suitable for or configured to perform additional tasks or steps. Additionally, the use of "based on" is meant to be open and inclusive, as a process, step, calculation, or other action "based on" one or more of the stated conditions or values ​​may in practice be based on additional conditions or values ​​beyond those stated. The headings, lists, and numbering included herein are for ease of explanation only and are not intended to be limiting.

[0097] It will also be understood that, although the terms "first", "second", etc. may be used to describe various objects in this article, these objects should not be limited by these terms. These terms are only used to distinguish one object from another object. For example, a first node may be referred to as a second node, and similarly, a second node may be referred to as a first node, which changes the meaning of the description, as long as all occurrences of the "first node" are consistently renamed and all occurrences of the "second node" are consistently renamed. Both the first node and the second node are nodes, but they are not the same node.

[0098] The terms used herein are only for describing specific implementations and are not intended to limit the claims. As used in the description of this specific implementation and the appended claims, the singular forms of "one", "a kind of" and "the" are intended to also cover the plural forms, unless the context clearly indicates otherwise. It will also be understood that the term "or" used herein refers to and covers any and all possible combinations of one or more items in the associated listed items. It will also be understood that the terms "including" or "comprising" when used in this specification specify the presence of stated features, integers, steps, operations, objects or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, objects, parts or their groupings.

[0099] As used herein, the term "if" may be interpreted to mean "when the antecedent is true" or "when the antecedent is true" or "in response to determining" or "upon determining" or "in response to detecting" that the antecedent is true, depending on the context. Similarly, the phrase "if it is determined that [the antecedent is true]" or "if [the antecedent is true]" or "when [the antecedent is true]" is interpreted to mean "upon determining that the antecedent is true" or "in response to determining" or "upon determining" that the antecedent is true or "when detecting that the antecedent is true" or "in response to detecting" that the antecedent is true, depending on the context.

[0100] The foregoing description and summary of the present invention should be understood to be illustrative and exemplary in every aspect, rather than restrictive, and the scope of the present invention disclosed herein is determined not only by the detailed description of the exemplary specific implementations, but by the full breadth allowed by the patent law. It should be understood that the specific implementations shown and described herein are only illustrative of the principles of the present invention, and that various modifications can be implemented by those skilled in the art without departing from the scope and essence of the present invention.

Claims

1. An electronic device, comprising: a frame comprising one or more light sources; an optical device coupled to the frame and comprising one or more waveguides positioned to direct light received from the one or more light sources of the frame to an exit location at a surface of the optical device, wherein the optical device comprises a second waveguide positioned to display augmented reality (AR) content, the second waveguide being different from the one or more waveguides; Image sensor; and A processor, the processor being configured to: receiving sensor data from the image sensor, the sensor data corresponding to reflections of the light emitted from the emission location and reflected from an eye; and Eye properties are evaluated based on the reflections.

2. The electronic device of claim 1, wherein one or more waveguides are transparent.

3. The electronic device of claim 1 , wherein the optical device comprises a plurality of layers, the plurality of layers comprising: A first layer comprising the waveguide to guide the light reflected from the eye.

4. The electronic device of claim 1, wherein the plurality of layers comprises: A second layer includes a second waveguide positioned to display augmented reality content.

5. The electronic device of claim 4, wherein the first layer comprises: a first portion, the first portion comprising a first transparent material having a first transparency index; and A second portion includes a second transparent material having a second transparency index greater than the first transparency index. The electronic device of claim 5 , wherein the first portion is an air gap.

7. The electronic device according to claim 4, wherein the optical device further comprises: The third layer includes a cover glass.

8. The electronic device according to claim 4, wherein the optical device further comprises a coloring layer.

9. The electronic device of any one of claims 1 to 8, wherein the optical device further comprises a prism, the prism comprising a reflective surface, the reflective surface directing the light to exit the optical device at the exit location.

10. An electronic device according to claim 9, wherein the prism or reflective surface is coated with a coating that is transparent to at least some light in the visible light range and is reflective to at least some of the light outside the visible light range generated by the one or more light sources.

11. The electronic device according to any one of claims 9 to 10, wherein each of the reflective surfaces is less than 75 μm x 75 μm.

12. The electronic device according to any one of claims 1 to 11, wherein the optical device further comprises a grating that directs the light to exit the optical device at the exit position.

13. An electronic device according to any one of claims 1 to 12, wherein the optical device comprises a glass layer in which the one or more waveguides are embedded.

14. An electronic device according to any one of claims 1 to 12, wherein the optical device comprises a layer of transparent polymer material in which the one or more waveguides are embedded.

15. The electronic device according to any one of claims 1 to 14, wherein the one or more waveguides are formed via a wafer patterning technique or a nano-imprinting technique.

16. The electronic device of any one of claims 1 to 15, wherein each of the one or more waveguides comprises: A polymer patterned by photolithography or laser; and A microprism comprising at least one facet coated to reflect light between 900 nm and 1000 nm.

17. The electronic device of claim 16, wherein each of the one or more waveguides further comprises: A filling structure has a lower refractive index than the polymer.

18. The electronic device of any one of claims 1 to 15, wherein each of the one or more waveguides comprises: A polymer patterned by photolithography or laser; and A reflective shape is embedded within a fill structure having a lower refractive index than the polymer.

19. The electronic device of any one of claims 1 to 18, wherein the one or more light sources comprise one or more vertical cavity surface emitting lasers (VCSELs).

20. The electronic device of claim 19, wherein each of the one or more vertical cavity surface emitting lasers (VCSELs) generates light between 900 nm and 1000 nm.

21. An electronic device according to any one of claims 1 to 20, wherein the exit locations are spaced apart from each other relative to the surface of the optical device to emit the light toward the eye from multiple directions.

22. The electronic device according to any one of claims 1 to 21, wherein the electronic device is a head mounted device (HMD).

23. A method comprising: At an electronic device having a processor: directing light through at least one waveguide to a plurality of exit locations on an optics of the electronic device, wherein the optics includes a second waveguide positioned to display augmented reality (AR) content, the second waveguide being different from the at least one waveguide; receiving sensor data from an image sensor, the sensor data corresponding to a plurality of reflections of the light reflected from an eye; as well as A characteristic of the eye is evaluated based on the sensor data.

24. The method of claim 23, wherein evaluating the characteristic of the eye comprises determining an orientation of the eye based on identifying a pattern of the multiple reflections of the light reflected from the eye.

25. The method of claim 23, wherein evaluating the characteristic of the eye comprises determining a gaze direction of the eye based on the multiple reflections of the light reflected from the eye.

26. The method of claim 23, wherein evaluating the characteristic of the eye comprises performing authentication.

27. The method of claim 26, wherein performing the authentication comprises identifying an iris of the eye.

28. A method according to any one of claims 23 to 27, wherein assessing the characteristic from the eye is based on sensor data from a single sensor.

29. A method according to any one of claims 23 to 28, wherein the optical device is configured to display content via a second waveguide.

30. A method according to any one of claims 23 to 29, wherein evaluating the eye characteristics includes determining the positions of multiple parts of the eye based on determining the positions of multiple flashes.

31. The method of any one of claims 23 to 30, wherein the light is infrared (IR) light.

32. The method of any one of claims 23 to 31, wherein the sensor comprises an image sensor, and receiving the reflected light comprises receiving the reflected light from image data from the sensor.

33. The method of any one of claims 23 to 32, wherein the electronic device is a head mounted device (HMD).

34. A non-transitory computer-readable storage medium storing program instructions executable on a device to perform operations comprising: directing light through at least one waveguide to a plurality of exit locations on an optics of an electronic device, wherein the optics includes a second waveguide positioned to display augmented reality (AR) content, the second waveguide being different from the at least one waveguide; receiving sensor data from an image sensor, the sensor data corresponding to a plurality of reflections of the light reflected from an eye; as well as A characteristic of the eye is evaluated based on the sensor data.

35. The non-transitory computer-readable storage medium of claim 34, wherein evaluating the characteristic of the eye comprises determining an orientation of the eye based on a pattern identifying the plurality of reflections of the light reflected from the eye.

36. The non-transitory computer-readable storage medium of claim 34, wherein evaluating the characteristic of the eye comprises determining a gaze direction of the eye based on the multiple reflections of the light reflected from the eye.

37. The non-transitory computer-readable storage medium of claim 34, wherein evaluating the characteristic of the eye comprises performing authentication.

38. The non-transitory computer-readable storage medium of claim 37, wherein performing the authentication comprises identifying an iris of the eye.

39. The non-transitory computer-readable storage medium of any one of claims 34 to 38, wherein assessing the characteristic from the eye is based on sensor data from a single sensor.

40. The non-transitory computer readable storage medium of any one of claims 34 to 39, wherein the optical device is configured to display content via a second waveguide.

41. A non-transitory computer-readable storage medium according to any one of claims 34 to 40, wherein evaluating the eye characteristics includes determining the positions of multiple parts of the eye based on determining the positions of multiple flashes.

42. The non-transitory computer readable storage medium of any one of claims 34 to 41, wherein the light is infrared (IR) light.

43. The non-transitory computer-readable storage medium of any one of claims 34 to 42, wherein the sensor comprises an image sensor, and receiving the reflected light comprises receiving the reflected light from image data from the sensor.

44. The non-transitory computer-readable storage medium of any one of claims 34 to 43, wherein the electronic device is a head mounted device (HMD).

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