Abstract: A wearable image manipulation system comprising a camera input system, an image projection system, where the image projection system is capable of being worn by a user, and a processor in communication with the camera input system and the image projection system such that the processor is capable of receiving an image from the camera input system, modifying the image to produce a modified image, and displaying the modified image on the image projection system. The camera input system may comprise a contact lens with a camera mounted thereon. Additionally or alternately, the system may be capable of tracking a user's eye movement to accurately capture where the user is looking with the camera input system.

Abstract: A wavefront calibration method for a wavefront tester of a lens, the method including: measuring an air wavefront of the wavefront tester without the lens; measuring at least one golden sample wavefront to generate an actual wedge angle and refractive index of the at least one golden sample based on the air wavefront; calculating a measured wedge angle and refractive index based on the actual wedge angle and refractive index of the at least one golden sample; and linear fitting between the actual wedge angle and refractive index and the measured wedge angle and refractive index to produce an actual magnification of the lens.

Abstract: An ophthalmologic apparatus includes an optical scanner, an interference optical system, an intraocular distance calculator, an image correcting unit, and a controller. The optical scanner is disposed at an optically substantially conjugate position with a first site of a subject's eye. The interference optical system is configured to split light from a light source into reference light and measurement light, to project the measurement light onto the subject's eye via the optical scanner, and to detect interference light between returning light of the light from the subject's eye and the reference light via the optical scanner. The image forming unit is configured to form a tomographic image of the subject's eye corresponding a first traveling direction of the measurement light deflected by the optical scanner, based on a detection result of the interference light.

Abstract: An ophthalmologic apparatus includes an optical scanner, an interference optical system, an intraocular distance calculator, an image correcting unit, and a controller. The optical scanner is disposed at an optically substantially conjugate position with a first site of a subject's eye. The interference optical system is configured to split light from a light source into reference light and measurement light, to project the measurement light onto the subject's eye via the optical scanner, and to detect interference light between returning light of the light from the subject's eye and the reference light via the optical scanner. The image forming unit is configured to form a tomographic image of the subject's eye corresponding a first traveling direction of the measurement light deflected by the optical scanner, based on a detection result of the interference light.

Abstract: A reality system includes a display aimed at a retina, the display providing 3D images with different depth view points; a glass to selectably turn on or off view of an outside environment in front of the person's eye; a processor coupled to the camera and to the glass to selectably switch between augmented reality and virtual reality; and a wireless transceiver coupled to the transceiver to communicate with a remote processor.

Abstract: [Problem(s) to be solved] To provide an eye contact detection device that achieves man-machine interface based on eye contact. [Means for solving problem(s)] An eye contact detection device according to the present invention includes: a light emitting element 200 for emitting light from an opening 260 in an optical axis direction; a light receiving element 220 for receiving light emitted from the light emitting element 200 and reflected off by the eyeball E of user to output an electrical signal in accordance with the received light; a detection circuit 230 for amplifying and binarizing an analog electrical signal output from the light receiving element 220, and an eye contact determination unit 240 for determining the presence or absence of eye contact of user U based on a detection signal output from the detection circuit 230.

Abstract: A system includes an image realisation device for forming a source image and projection optics for rendering a display image on a display screen, wherein the display image is a virtual image corresponding to the source image. The projection optics have an optical axis, and the image realisation device includes a first image realisation surface at a first distance along the optical axis and a second image realisation surface at a second, different distance along the optical axis. The first and second image realisation surfaces overlap, and the first and second image realisation surfaces include multiple regions, each region switchable between a transparent state and an image realisation state such that the source image may be formed on a region of the first or second image realisation surface and projected through the projection optics to render the display image on the display screen at a first or second apparent depth.

Abstract: An eyeball tracking system is provided, which includes: an illumination light source, configured to transmit an illumination light ray to a beam scanner; the beam scanner, configured to project the illumination light ray onto an entrance pupil optical apparatus; the entrance pupil optical apparatus, configured to reflect, reproduce, or refract the illumination light ray, so that the reflected, reproduced, or refracted illumination light ray illuminates an eyeball; a photoelectric detector, configured to: collect a receive optical power value of an eyeball reflection light ray, and send the receive optical power value to a controller; and the controller, configured to: receive the receive optical power value sent by the photoelectric detector, determine, based on the receive optical power value, an optical power reference value, and determine a current gaze direction of the eyeball based on the optical power reference value.

Abstract: A method, a device, and a corresponding computer program product for calculating (optimizing) and producing a spectacle lens with the aid of a semi-personalized eye model. In one approach, the method includes providing personalized refraction data of at least one eye of the spectacles wearer; establishing a personalized eye model in which at least the parameters: shape of an anterior corneal surface of a model eye; a cornea-lens distance; parameters of the lens of the model eye; and lens-retina distance are established using personalized measured values for the eye of the spectacles wearer, and/or using standard values, and/or using the provided personalized refraction data, such that the model eye has the provided personalized refraction data, wherein at least the establishment of the lens-retina distance takes place via calculation.

Abstract: A subjective optometry apparatus has a projection optical system including a visual target presenting portion and an optical member to project a target light flux toward a subject eye, and causing the target light flux to be incident on the optical member with a deviation of the incident target light flux from an optical axis of the optical member, a housing accommodating the projection optical system, a presentation window for emitting the target light flux from the inside of the housing to the outside thereof, an eye refractive power measurement unit provided outside the housing, and holding means integrally connecting the housing to the eye refractive power measurement unit to hold the eye refractive power measuring unit. When using the eye refractive power measuring unit, a distance from the presentation window to the eye refractive power measurement unit in an optical path is equal to or less than 180 mm.

Abstract: Ophthalmic imaging systems, particularly slit-scanning ophthalmo-scopes, are capable of characterizing refraction over the entire field of view of the system. Light from the light source of the system illuminates a region of the eye and the returning light is measured on a detector. The deviation of the location of the returning light from a predetermined location on the detector is measured. The deviation corresponds to the mismatch between the refractions of the imaging system and the eye. The light can be scanned across the full field of view to characterize the entire field. A second illumination source traveling along a second illumination path can be used to improve the characterization. The characterization can be of use for optimizing the focus of the instrument and for assessing the condition of the eye, including assessing myopia and astigmatism in the periphery.

Abstract: Improved optical coherence tomography systems and methods to measure thickness of the retina are presented. The systems may be compact, handheld, provide in-home monitoring, allow the patient to measure himself or herself, and be robust enough to be dropped while still measuring the retina reliably.

Abstract: A surgical instrument includes a light guide configured to convey light energy, a lens configured to focus the light energy into a light beam, a mounting tube, a jaw assembly coupled to the mounting tube, and a handle assembly. The jaw assembly includes a first jaw member non-movably secured to the mounting tube, a second jaw member movably secured to the mounting tube, and a window secured to the first jaw member and forming a tissue contacting surface. The window is oriented in a plane oblique to a longitudinal axis of the mounting tube and forms a liquid-tight seal between tissue and the lens. The handle assembly is coupled to the jaw assembly to move the second jaw member between an open position in which the second jaw member is spaced part from the window and a closed position.

Abstract: According to various, but not necessarily all, embodiments there is provided an apparatus comprising means for: capturing at least one image of a cornea of the user; processing the at least one image to detect one or more objects and/or activities based on one or more reflections by a peripheral portion of the cornea; and providing an alert to the user for alerting the user to the detection of the one or more objects and/or activities.

Abstract: Measurement of intraocular lengths by dual-beam Fourier low-coherence interferometry on the basis of Fresnel-zone-type space-time domain interferograms of the Purkinje-Sanson reflexes. The eye is illuminated by parallel, monochromatic dual beams having wavelengths which differ in temporal sequence. Wavelength spectra of space-time domain interferograms are imaged onto a photodetector array and registered. Viewing direction and position of the eye are fixed by optical aids and are monitored by acoustic and optical aids. A zoom optical unit in the output beam of the ophthalmological interferometer makes it possible, by simple focusing, to image virtual Fresnel-zone-type space-time domain interferograms from contrast-optimized positions onto the photodetector array or onto an image intensifier that is arranged in front of the photodetector array such that the position-dependent size change of the space-time domain interferograms is compensated by the scale change of this imaging.

Abstract: Disclosed are training method, program and computing device to ameliorate visual field defect. The method includes presenting, by a computer, a virtual first object on a screen, wherein the first object is presented in an approaching manner toward the subject from a first position to a second position, when a position of the first object reaches the second position, the dividing, by the computer, of the first object into objects and presenting the divided objects on the screen or removing, by the computer, the first object from the screen, when the first object is divided or removed, presenting, by the computer, a virtual second object and a virtual third object on the screen, and receiving, by the computer, an identification input about the second object and the third object from a response input device of the subject.

Abstract: There is described an artificial eye system comprising: a see-through display for displaying an image of an eye thereon; a light detector for detecting light propagating through the see-through display and coming from an external environment; and a controller for: generating the image of the eye using information about the light detected by the light detector; and displaying the generated image of the eye on the see-through display.

Abstract: The invention relates to glasses provided with two transparent spectacle glasses enclosed in a frame. Each spectacle glass is positioned in front of a person's eye with the aid of a frame to be positioned on the ears and nose of said person. The glasses are further provided with at least one light source integrated in the frame for directly and/or indirectly delivering light to the eyes substantially from above. A nose frame part of the frame reflects at, at least, a nose frame side portion facing the eye, to the eye at least partially the direct or indirect incident light thereon originating from the light source.

Abstract: The invention relates to an OCT system with an OCT light source for emitting OCT light into an object beam path and a reference beam path. The system comprises a detector for detecting an interference signal produced by the object beam path and the reference beam path. A polarization-dependent delay element is arranged in the object beam path. The invention also relates to a corresponding OCT method. The invention allows the effects of parasitic reflections to be reduced.

Abstract: A system and method for stimulus & eye tracking, useful for the determination of the presence or strength of optokinetic nystagmus (OKN) typically for assessing visual acuity, comprises providing a novel visual stimulus effective to elicit OKN, which includes varying the visibility of a visual stimulus element, or displaying a series of visual stimulus elements so that a later displayed element has different visibility relative to an earlier displayed element. Visual stimulus elements may vanish or appear by reducing or increasing intensity, contrast, size and/or width of the elements or element boundaries. Visual stimulus elements comprise a perimeter that is darker than a background and a centre that is lighter than the background, and/or a perimeter that is lighter than a background and a centre that is darker than the background.

Abstract: A reality system includes a display aimed at a retina, the display providing 3D images with different depth view points; a glass to selectably turn on or off view of an outside environment in front of the person's eye; a processor coupled to the camera and to the glass to selectably switch between augmented reality and virtual reality; and a wireless transceiver coupled to the transceiver to communicate with a remote processor.

Abstract: A total internal reflection prism unit may include a first prism and a second prism. The first prism may include a first total reflection surface, which totally reflect slight incident in a first horizontal direction along a second horizontal direction substantially perpendicular to the first horizontal direction, and a second total reflection surface, which totally reflects the totally reflected light from the first total reflection surface along the first horizontal direction to form a first beam. The second prism may include a third total reflection surface, which totally reflects the light along a third horizontal direction substantially perpendicular to the first horizontal direction, and a fourth total reflection surface, which totally reflects the totally reflected light from the third total reflection surface along the first horizontal direction to form a second beam. The second beam may be discrete from the first beam along the third horizontal direction.

Abstract: An eyeball tracking system is provided, which includes: an illumination light source, configured to transmit an illumination light ray to a beam scanner; the beam scanner, configured to project the illumination light ray onto an entrance pupil optical apparatus; the entrance pupil optical apparatus, configured to reflect, reproduce, or refract the illumination light ray, so that the reflected, reproduced, or refracted illumination light ray illuminates an eyeball; a photoelectric detector, configured to: collect a receive optical power value of an eyeball reflection light ray, and send the receive optical power value to a controller; and the controller, configured to: receive the receive optical power value sent by the photoelectric detector, determine, based on the receive optical power value, an optical power reference value, and determine a current gaze direction of the eyeball based on the optical power reference value.

Abstract: Mechanical optics for mode mixing may be used to homogenize different modes in an optical fiber used for surgical illumination. A mechanical optical element, such as a rotating prism or a mirror membrane, may impart motion to an incident beam entering the optical fiber to generate a homogeneous illumination field from a coherent light source.

Abstract: In one example, a method includes instructing a pattern projector of a distance sensor to project a pattern of light onto the object, wherein the pattern comprise a plurality of parallel rows of projection artifacts, and wherein a spatial density of the projection artifacts in a first row of the plurality of parallel rows is different from a spatial density of the projection artifacts in a second row of the plurality of parallel rows, instructing a camera of the distance sensor to acquire an image of the object, where the image includes the pattern of light, and calculating a distance from the distance sensor to the object based on an analysis of the image.

Abstract: A scene presented by a headset is adjusted to correct for distortion from optical errors of an optics block in the headset. To correct for the distortion, the scene is pre-distorted when presented based on previously modeled distortion of the optics block, so distortion from the optics block corrects the pre-distortion. To model the distortion, the headset displays calibration image including features and images of the calibration image are captured from multiple positions. Differences between locations of features in the calibration images and locations of corresponding features in captured images of the calibration image are identified and a distortion correction is determined based on the differences.

Abstract: An eye-examining apparatus in which a visible light optical system for observing a shape of an examinee's eye and an infrared optical system for detecting a shape of the cornea of the examinee's eye are integrated. The eye-examining apparatus having an integrated optical system comprises: an infrared light source for irradiating a cornea of the examinee's eye with infrared light; a visible light source for irradiating the eye with visible light; an image detector both for detecting an image of the infrared light which is irradiated from the infrared light source and reflected from the cornea of the eye and for detecting an image of the visible light which is irradiated from the visible light source to the eye; and a visible light blocking filter inserted in an optical path of the visible light and the infrared light traveling toward the image detector for blocking the visible light.

Abstract: A display system useful for achieving a wide field of view infinity effect. The system includes a frame assembly adapted for mounting on a wall of viewing space. The system includes a display element with a display surface. The system includes a magnifying lens supported within the frame assembly with a rear surface facing the display surface and with a front surface facing the viewing space. The rear surface of the magnifying lens is parallel to the display surface of the display element and is separated from the display surface by a separation distance less than a focal length of the magnifying lens, e.g., a value such that a ratio of the separation distance to the focal length is in the range of 0.169 to 0.254. The magnifying lens may be a Fresnel lens in the form of a planar plastic sheet manufactured to provide a flat spherical lens.

Abstract: A method for updating an index of a person, the method includes: an index providing during which an index is defined as a function of at least one parameter related to the person is provided; a parameter monitoring during which the at least one parameter of the person is monitored over time; an index update during which the index of the person is updated based on the evolution over time of the at least one parameter of the person.

Abstract: A high-performance single-chip, integrated-optics-based OCT system is disclosed, where the length of the reference arm is digitally variable. The reference arm includes a plurality of switch stages comprising a 2×2 tunable wavelength-independent waveguide switch that can direct an input light signal onto either of two different-length output waveguides. In some embodiments, the directional couplers are thermo-optic based. Some embodiments include a solid-state scanning system for scanning a sample signal along a line of object points on the sample under test.

Abstract: A device for producing control data for a laser device for the surgical correction of defective vision. The device generates the control data to control the laser, the optics and the scanner to cut the cornea by focusing the laser radiation and by shifting the position of the focus within the cornea. The control data controls the scanner to shift the position of the focus within the cornea. The device generates the control data such that the laser, the optics and the scanner emit and focus the laser radiation such, that a volume in the cornea is isolated. The removal of which volume from the cornea effects a desired correction of the defective vision. To determine the control data, the device is configured to calculate a radius of curvature Rcv* of the cornea reduced by the volume wherein the radius of curvature Rcv* is locally varying.

Abstract: Described herein is a human eye emulator device that emulates the human eye's responses to light. The human eye emulator device is based on an electro-optical liquid crystal eye model. The human eye emulator device includes a Pancharatnam berry phase (PBP) liquid crystal (LC) lens, a liquid crystal (LC) shutter glass, and a liquid crystal (LC) lens. The PBP LC lens emulates the cornea. The PBP LC lens receives light and refracts the received light. The LC shutter glass emulates the pupil. The LC shutter glass forms a dynamic aperture that transmits a portion of the light refracted by the PBP LC lens. The LC lens emulates the crystalline lens. The LC lens receives the portion of light transmitted by the LC shutter glass and refracts the received portion of light through the LC shutter glass onto an imaging surface.

Abstract: A patient simulator having a right eye assembly including a right pupil, a right eyelid assembly including a right eyelid, a left eye assembly including a left pupil, a left eyelid assembly including a left eyelid, a transmitter configured to transmit a signal toward an object placed in front of the patient simulator, a sensor configured to sense a signal reflected off the object, and a microprocessor configured to determine a location of the object based on the sensed signal, and to effect movement of one or more of the right pupil, the right eyelid, the left eye, or the left eyelid based on the determined location of the object.

Abstract: A method and device for non-invasive monitoring of the temperature of the retina and the retinal pigment epithelium inside the eye, particularly during heating of the bottom of the eye, wherein alternating probing short-duration pulses of light, one at wavelength close to the absorption maximum of the photoreceptor cell type and the other at wavelength in the near-infrared region, are directed at the retinal tissue at appropriate time intervals. Photoreceptor cell electrical signals, photoresponses, are recorded using electroretinography (ERG) and the changes in retinal temperature are determined from changes in photoresponse kinetics and changes in photoreceptor sensitivity to the stimuli. The method is especially applicable at temperatures up to 45° C. for humans and for other animals.

Abstract: One embodiment provides a method including: capturing, using a camera on a device, at least one image of a user viewing a display of the device; and adjusting, using a processor, a brightness setting of the display from a first setting to a second setting based on the at least one image. Other aspects are described and claimed.

Abstract: A parallel detecting optical coherence tomography (OCT) setup and method, in which the light paths of the illumination of the sample and of the detection of the backscattered light do not use the same apertures. The separation of illumination and detection apertures filters these disturbing reflexes from the backscattered light of the sample and significantly increases image quality.

Abstract: A disposable eye piece system, including the eye piece and other disposable components, for a precision ultrasonic scanning apparatus is disclosed. The eye piece includes a fill port, a vent port and a drain port molded into the base of the eye piece. An RF Identification chip may be molded into the plastic base of the eye piece or, alternately into the conformable face seal of the eye piece. The components of a disposable eye piece system form an integrated disposable package that can be assembled, packaged, transported and used while maintaining the eye piece and saline solution in a sterile condition. The protective shipping container 1) protects the eye piece from damage, human contact and exposure to ambient air during shipping and storage and 2) allows the scanning physician or technician to attach the eye piece to the scanning machine without compromising the sterile condition of the eye piece.

Abstract: The invention relates to a method for highly accurate determining of a pupil diameter of an eye, using a camera system for spatial capturing of objects, the method including: imaging stereoscopic capturing of an eye region, wherein for an eye of the eye region a first and a second stereoscopic image arise. For each of the two stereoscopic images the method further includes: Transferring of the captured eye region into a color space. Determining of a region, within the captured eye region, as a region within a pupil of the captured eye region. Determining of a closed outer edge of the region within the pupil. Iterative determining of a closed outer pupil edge. The invention further relates to a corresponding device.

Abstract: A device for determining biometric variables of the eye, as are incorporated in the calculation of intraocular lenses including a multi-point keratometer and an OCT arrangement. The keratometer measurement points are illuminated telecentrically and detected telecentrically and the OCT arrangement is designed as a laterally scanning swept-source system with a detection region detecting the whole eye over the whole axial length thereof. The multi-point keratometer ensures that a sufficient number of keratometer points are available for measuring the corneal surface. By contrast, telecentricity ensures that the positioning inadequacies of the measuring instrument in relation to the eye to be measured do not lead to a local mismatch of the reflection points. The swept-source OCT scan detects the whole eye over the length thereof so that both anterior chamber structures and retina structures can be detected and a consistent whole eye image can be realized.

Abstract: An inspection system for detecting a particle in a transparent cylinder having a longitudinal axis and a diameter includes a light source able to illuminate a transparent cylinder, a mask able to block at least part of the light coming from the light source, the light source and the mask being arranged such that, when the transparent cylinder is positioned in the system for inspection, the light source, the mask and the transparent cylinder are substantially aligned along an inspection axis perpendicular to the longitudinal axis of said transparent cylinder and the mask is interposed between the light source and the transparent cylinder so as to prevent illumination of a first portion of the transparent cylinder having a width smaller than the diameter of the transparent cylinder while allowing illumination of a second portion of the transparent cylinder, the mask being configured to provide a contrast with a particle present in the first portion of the transparent cylinder and illuminated by light refracted

Abstract: A method and system for determining visual related physical conditions of a user of a display device, determined from the user's responses to a selection of visual-tasks. A dataset is provided for correlating the user's responses with the corresponding scores, so that by measuring the degree of correlation between the user's scores and a predetermined combination of the corresponding scores, the user's visual physical condition can be determined. A system is also provided, including a user device as well as a remote server for providing visual acuity and related testing to detect certain vision deficiencies and visual related physical conditions. In addition, a user device application is provided.

Abstract: Described herein is a light directing assembly for use in an object analysis system. The light directing assembly includes a plurality of optical relay assemblies. Each optical relay assembly includes at least one optical element configured to relay an interrogation beam from a light transmission system to an object and relay a return beam from the object to the light transmission system, the return beam being generated by reflection or back scattering of the interrogation beam by the object. Each optical relay assembly defines an interrogation angle at which the interrogation beam relayed by the optical relay assembly reaches the object, and an optical path length being the distance from the light transmission system to the object travelled by an interrogation beam via the optical relay assembly.

Abstract: A device can include a first transparent display having a at least one pixel, wherein transparency of the at least one pixel is electronically controlled, and a second transparent display configured to emit an image. Selected regions of the image are shown by having regions of the second transparent display corresponding to the selected regions of the image be transparent and regions of the first transparent display corresponding to the selected regions of the image appear opaque.

Abstract: A display system includes a display and a computer. The computer is configured to cause the display provide a visual cue in a far or mid peripheral vision area of the display with respect to a user's forward looking view through the display. The display system can be a head up display (HUD) on a worn display for use in aircraft or other applications.

Abstract: Improved eyewear is disclosed. The eyewear comprises a frame member and a lens. The eyewear also includes circuitry within the frame member for enhancing the use of the eyewear. A system and method in accordance with the present invention is directed to a variety of ways to enhance the use of eyeglasses. They are: (1) media focals, that is, utilizing the eyewear for its intended purpose and enhancing that use by using imaging techniques to improve the vision of the user; (2) telecommunications enhancements that allow the eyeglasses to be integrated with telecommunication devices such as cell phones or the like; and (3) entertainment enhancements that allow the eyewear to be integrated with devices such as MP3 players, radios, or the like.

Abstract: The invention relates to a device for acquisition of images for a biometric system, which includes an optical assembly and at least one imager for acquisition of an image of an object to be analysed presented in front of the assembly at a non-determined distance from the latter. The assembly includes at least one diaphragm with a coded aperture. The optical assembly allows acquisition by the sensor(s) of an image of the object capable of being exploited to deduce therefrom the searched biometric information, and of an image of the object acquired via the coded aperture of the diaphragm. The device also includes a processing unit to determine the distance of the object to be analysed as a function of the image of the object acquired via the coded aperture of the diaphragm.

Abstract: The present invention relates to an ophthalmic treatment apparatus and to a treatment beam radiating method for the apparatus. The ophthalmic treatment apparatus according to the present invention comprises: a beam generating unit for generating a treatment beam; a beam delivery unit for delivering the treatment beam generated by the beam generating unit to the retinal region of an eyeball; an image unit for forming an image of the retinal region of the eyeball in the horizontal direction with respect to the plane of the focal spot of the treatment beam guided by the beam delivery unit; and a control unit for controlling the beam delivery unit such that the location of the plane of the focal spot can be adjusted based on the curvature of the retinal region of the eyeball imaged by the image unit.

Abstract: A method and apparatus for modelling a lens (104) of an eye (100), comprising: measuring (302) the anterior shape of the eye's cornea (102); determining (304) direct optical measurements of at least one parameter of the cornea (102) of the eye (100) and at least one parameter of the lens (104) of the eye (100); determining (306) the refractive index of the cornea; correcting (308) the optical measurements to account for the effect of the refractive index of the cornea on the direct optical measurements; measuring (310) the aberration of the eye; calculating (312) the refractive index of the lens by combining the corrected measurements and the aberration; and further correcting (314) the optical measurements of the lens to account the effect of the refractive index of the lens on the direct optical measurements.

Abstract: An image projection device includes: one light source unit emitting an image light beam, which forms an image, of visible light and a checking light beam of visible light; an optical system projecting the image light beam emitted from emitted from the one light source unit onto a first surface region of an eye of a user to project the image light beam onto a retina of the user, and projecting the checking light beam emitted from the one light source unit onto a second surface region, which is distant from the first surface region, of the eye of the user; a light detector detecting a reflected light that is the checking light beam reflected by the eye of the user; and a controller controlling at least one of the one light source unit and the optical stem based on a detection result of the reflected light by the light detector.

Abstract: Systems and methods for assessing the visual acuity of person using a computerized consumer device are described.