32 results about "Corneal reflex" patented technology

The corneal reflex method is used to detect the current direction of view (VD) of a user (UE) to perform specifically selected functions on a computer. Eye vectors (EV) can be detected between the pupil center (ZP) and reflection points (RP) on the cornea (CA) that can be associated with a fixation point (FP) on a computer screen using infrared light (IRS). The association is produced as a function of the direction of view (VDF), so the relationship is detected during an initial calibration (C) by a referenced user (RE) to develop a set of reference eye vectors (EVR). A shorter self-balancing recalibration (RC) is then carried out for each subsequent user (UE). A mapping function (MF) is detected during the recalibration (RC) so that the individual eye vectors (EVU) can be converted to the reference eye vectors (EVR) by the mapping function. The recalibration (RC) can take place without the user (UE) realizing it. The method is useful in medical diagnostics, psycho-optical examinations and eye-controlled interaction with multimedia computers.

An apparatus (10, 10′) for detecting the surface topography of a cornea (24) of an eye (22) by dynamic or static projection of a pattern onto the surface of the cornea and detection of the pattern reflected by the cornea, providing preferably simultaneous detection of at least one optical property of a layer disposed beneath the cornea.

A system and method for locating and modeling eyes in imagery for automated photorefractive screening. The invention includes a digital camera having a lens-mounted flash for obtaining a digital image of the face of an individual, and a suitably programmed processor, such as a general purpose digital computer, for locating an eye of the individual in the digital image, modeling structures in the eye, analyzing the digitized eyes of the individual for eye disease, and providing a recommendation for treatment. In one aspect, the invention includes a system and method for locating a patient's eyes in a digital image that includes each eye as illuminated by a near-axis flash, including automatically finding light reflexes in the digital images as indicative of the location of each eye. Automatically finding light reflexes includes analyzing such light reflexes to determine possible pupil and sclera borders. The invention further includes automatically fitting a corresponding model to such possible pupil and sclera borders, analyzing the model of each eye to determine possible abnormalities in each eye; and outputting a possible diagnosis for each eye based on such analyzing. Other aspects of the invention include measuring retinal reflexes and corneal reflexes from the indicated eye models as an indicator of anomalies in the patient's eyes, and generating a digital image of each of a patient's eyes with a camera having a flash positioned near to a center line of a lens of the camera so as to generate images with bright, sharp light reflexes.

The invention provides a non-contact sight tracking method based on corneal reflex. The method comprises steps as follows: step one, positioning of human eyes; steps two, calculation of light spot coordinates; step three, accurate positioning of pupils; and step four, space mapping: mapping of space coordinates is performed according to the calculated coordinates of four light spots on a screen, the coordinates of the pupil centers and the invariant principle of a cross ratio in the projective geometry. According to the provided technical scheme, a user doesn't need to wear other devices, so that limitation to the user is reduced greatly; a new pupil edge fitting scheme is proposed and used for circularly fitting and rejecting ideal points, so that the accurate pupil center is obtained, and the mapping accuracy is improved; and compared with the conventional correlational research, the accuracy is improved greatly.

A corneal hydration sensing system includes an illumination system configured to provide an illumination beam of terahertz radiation, an optical system arranged in an optical path of the illumination system to relay and direct at least a portion of the illumination beam of terahertz radiation onto a cornea of a subject and to receive at least a portion of terahertz radiation reflected from the cornea to provide a return beam of terahertz radiation, and a detection system arranged in an optical path of the return beam of terahertz radiation. The detection system is configured to provide a detection signal from detecting at least a portion of the return beam of terahertz radiation. The corneal hydration sensing system also includes a signal processing system configured to communicate with the detection system to receive the detection signal. The signal processing system processes the detection signal to provide a measure of an amount of hydration sensed in the cornea of the subject.

An ophthalmologic apparatus is configured to determine a direction in which a target that is used to adjust a working distance comes into focus based on an influence of astigmatism contained in a cornea reflection image of an eye to be examined.

A cornea shape measurement apparatus outputs data useful for prescription as well as injection and installation of a TORIC-IOL. This apparatus includes: a projecting optical system projecting an index for measurement onto a cornea; an illuminating optical system illuminating an anterior segment on which a reference mark is placed; an imaging optical system capturing an anterior segment image containing the reference mark and an image of the index reflected from the cornea; an image processor overlaying an astigmatic axis mark indicating a direction of an astigmatic axis of the cornea, which is calculated based on the index image, on the anterior segment image; and a controller displaying the anterior segment image, which contains the astigmatic axis mark, on a display.

The invention discloses a fundus camera optical system for aligning working positions of human eyes and a position aligning method. The working principle of an aligning optical path is as follows: one parts of a first light beam and a second light beam which are generated by a double-beam generation device are reflected by a second beam splitter after passing through a first beam splitter, and the reflected parts are incident into the human eye via an eye objective lens after passing through a first diaphragm with a hole; the two light beams are reflected back by the corneal, passes through the eye objective lens and the first diaphragm with the hole and are incident into the second beam splitter and reflected by the second beam splitter to the first beam splitter; a probe is adjusted so that the two light beams are just gathered on an imaging device, and at the moment, the imaging device displays two spots which are overlapped on each other and generated by focusing the two light beams on the imaging device, and then the working position of the vertex of the corneal in a fundus camera is judged according to the two spots overlapped on each other. As the aligning optical path does not comprise a diopter lens, the alignment of the working position is not affected by refractive adjustment, and therefore, even for different human eyes, the vertex of the corneal in the fundus camera is well-determined.

An alignment system for an ophthalmic instrument comprises an optical axis along which an operator can directly view the patient's eye and the patient can fixate on a dark fixation target surrounded by a bright background that helps to illuminate the eye for operator viewing. A position detection system utilizing stored geometrical relationships determined by multiple regression during instrument calibration compu tes X-Y-Z alignment status of the instrument relative to a patient's eye based on local x -y position information from a pair of lateral detectors receiving corneally reflected light from a corresponding pair of lateral light sources. A heads -up display im age is provided along an optical axis of the instrument for supplying instructive cues to an operator for moving the instrument to achieve alignment based on signal information from the position detection system, whereby the operator sees both a direct mac ro-image of the patient's eye and the display image. The alignment system is particularly suitable for use in hand-held ophthalmic instruments.

A method of compensating for misalignment between an optical measurement instrument and a model eye includes: receiving a light beam from the model eye at the optical measurement instrument; producing image data, including light spot data for a plurality of light spots, from the received light beam; determining an observed location of a corneal reflex from the model eye within an image representing the image data; and determining an angle of misalignment between an axis normal to the front surface of the model eye and the optical axis of the optical measurement instrument from the observed location of the corneal reflex within the image.

An ophthalmoscope has illuminating optics (10) for projecting a beam of light into an eye under examination and imaging optics (14) for creating an image of said eye for viewing by a user. The imaging optics comprises an objective lens system (16) and an eye piece lens system (20). Two corneal reflex stops (138 and 148) are positioned one on either side of the corneal image formed by the objective lens system. The stops block reflections from the cornea of the eye under examination over a range of distances of the ophthalmoscope from the eye. The use of the two corneal reflex stops results in the precise positioning of the ophthalmoscope relative to the eye under examination not being critical to the blocking of the corneal reflex.

A corneal reflex position detection device includes a pupil detecting unit that detects the center position of the pupil from an image of an eye of a test subject; and a corneal reflex detecting unit that detects the corneal reflex area from the image. The corneal reflex detecting unit enlarges, in a stepwise manner, a detection target area with reference to the center position of the pupil, to detect whether or not a high-luminance area having the luminance to be equal to or greater than a luminance threshold value is present in the image; and, if the high-luminance area is detected, determines that the high-luminance area represents the corneal reflex area.

The invention belongs to the technical field of intelligent wearing, discloses an eyeball tracking device and eyeball tracking equipment, and the device and the equipment are designed for solving theproblem that an existing eyeball tracking device based on a pupil-corneal reflex method is easily interfered by ambient light. The eyeball tracking device comprises a mounting frame, an eyeball tracking assembly and a light shield. The mounting frame is used for being connected with a head-mounted device. The eyeball tracking assembly and the shading cover are both arranged on the mounting frame,and the shading cover can be arranged between the mounting frame and the face of a user in a surrounding mode. The eyeball tracking equipment comprises a head-mounted device and the eyeball tracking device. The eyeball tracking device and the eyeball tracking equipment are used for realizing eyeball tracking.

A method for fixing the eyeball of a living mouse comprises the steps that 1, the mouse is anesthetized with 4.3% chloral hydrate based on the rate of 0.1ml/10g, and it can be observed that all muscles of the mouse relax, breathing is steady, and corneal reflex is blunt five minutes after anesthetization; 2, the limbs of the mouse are fixed to a surface plate with clips, and the area around the eyelid of the mouse is scrubbed with iodophor; 3, under an electron microscope, a handle of a mouse eyeball snare is held with the index finger and thumb of the left hand, the annular structure of the mouse eyeball snare is pressed down from top to bottom right facing the upper surface of the eyelid of the mouse, the eyeball of the mouse is trapped and fixed by the annular structure after the eyelid of the mouse is pushed away by the annular structure, the eyeball of the mouse protrudes upwards out of the plane of the annular structure at the moment, and the annular structure is pressed downwards continuously till veins on the sclera of the eyeball of the mouse are exposed clearly.