Abstract: A system and method for calibration-free tracking of a user's eye gaze vector and point of regard even if substantial head movement or rotation occurs. The preferred embodiment includes two synchronized interlaced cameras, each viewing the user's eye and having on-axis lighting that is alternately modulated. An image difference between lighted and unlighted images of the eye is used to identify a user's pupil. A plane containing the gaze vector is defined by rotating a base plane through the angle in a camera image plane between a pupil center, a first glint, and a second glint. The intersection of two such planes (one from each camera), defines the gaze vector. The gaze position is the intersection of the gaze vector with the object being viewed by the user. Alternate embodiments are also described.

Abstract: The present invention provides a power operated instrument stand for use, for example during eye examinations. The instrument stand has a motorized arm to aid in precise placement of instrumentation. The instrument stand also has control circuitry for room lighting levels, patient chair positioning and slit lamp operation. The instrument stand may be controlled through an attached control pad, or a remote control.

Abstract: An improved ophthalmic instrument including an integral wavefront sensor and display device, wherein the wavefront sensor measures phase aberrations in reflections directed thereto to characterize aberrations of the eye and is operably coupled to the display device, which displays a graphical representation of the aberrations of the eye. Such graphical representation may include: two dimensional contour maps that graphically depict contribution of pre-specified terms (such as spherical aberration, astigmatism and coma) for the aberrations of the eye, coefficients corresponding to such pre-specified terms that characterize the aberrations of the eye, or predefined two-dimensional icons that provide a general graphical depiction of such prespecified terms.

Abstract: One embodiment of the present invention is a visual field tester that includes: (a) a projection screen; (b) a stimulus projection system that projects a light source onto a first side of the projection screen; (c) a background projection system that projects a background light onto the first side of the projection screen; and (d) a magnifier lens system disposed on a second side of the projection screen that directs light transmitted through the projection screen to a predetermined location.

Abstract: A system and method for controlling an eye movement tracker includes monitoring a plurality of eye positions by following a feature using the tracker. An optical beam is sent into the eye, and an intensity of a reflected beam from the eye is sensed at each position. If the intensity of the reflected beam fluctuates from a predetermined acceptable intensity range, the tracker is returned to a frozen position. The frozen position comprises a most recent position at which the intensity lay within the intensity range. The tracker is also frozen if the noise in the signal exceeds a predetermined acceptable maximum noise level and for counting a number of times the tracker is frozen. The procedure is aborted if the tracker is frozen repeatedly and for a time exceeding a predetermined maximum acceptable time.

Abstract: A method and apparatus for improving the resolution of fundus images and correction of optical aberrations is described in which a bundle of electromagnetic beams is directed into an optical system and the reflected electromagnetic beams are recorded by a sensor. A processor may control the energy source to provide a plurality of different electromagnetic bundles to image the entire optical system. The reflected electromagnetic beams recorded by the sensor are compared to the original electromagnetic bundle configurations to calculate the aberrations of the optical system of interest. Among other applications, the calculated aberrations may be used to construct accurate fundus images, provide input for laser surgery of the eye, fabricate corrective lenses and provide accurate digital images of structures sensed through imperfect optical systems.

Abstract: Methods and apparatuses are provided for performing optical imaging on a sample. The method and apparatuses continually adjust the path-length of a reference arm or data acquisition in a manner such that imaging information is obtained only from a longitudinal range that contains a selective portion of a sample from which imaging information is to be obtained. The apparatuses include a starting point adjustment device that determines a point with respect to a sample at which imaging information collection is to be started. A controller then controls a second scanning mechanism, in addition to a first scanning mechanism, such that imaging information is obtained only from a longitudinal range that contains a selective portion of a sample from which imaging information is to be obtained. In this way, the amount of data collected can be reduced to that within the area of interest.

Abstract: An ophthalmic error measurement system includes a projecting optical system delivering light onto a retina of an eye, a pre-correction system which compensates a light beam to be injected into the eye for aberrations in the eye, the pre-correction system being positioned in between the projecting optical system and the eye, an imaging system which collects light scattered by the retina, and a detector receiving light returned by the retina from the imaging system. Use of the pre-correction system allows the end-to-end aberrations of the ocular system to be analyzed. The use of a pre-correction system also allows use of a minimized spot size on the retina, and all of its attendant advantages.

Abstract: A glaucoma diagnosis apparatus for determining thickness of nerve fiber layers. The apparatus includes an illuminating optical system for illuminating the ocular fundus of an eye to be examined with circularly polarized illuminating light and an imaging optical system including a CCD camera for photographing the image of an ocular fundus based on the reflected illuminating light from the ocular fundus and has a polarizing filter provided integrally with the imaging surface of the CCD camera. The filter includes repetitions of a unit platelet having a couple of polarizing microplates which transmit those linearly polarized light components crossing with each other out of the reflected illuminating light and adjacent polarizing microplates which transmit linearly polarized light components in direction crossing with both of the above/mentioned linearly polarized light components of the reflected illuminating light.

Abstract: The present invention discloses an apparatus and a method for measuring aberrations in the human eye by utilizing the tracking of rays of light to measure the aberration in the human eye. The displacement of the incident light with respect to the ideal point position in the eye is corrected by changing the incident angle of the incident light so as to superimpose with the ideal light point. The variation of the incident light is analyzed by least mean square procedure so as to obtain the two-dimensional wave aberration profile and the magnitudes of independent aberrations. The apparatus comprises light sources, optical system, means for changing the incident position of the incident light, means for changing the incident angle of the incident light, and computer control means.

Abstract: The present invention is intended to provide an eye characteristic measuring apparatus having a projection system for projecting a light source image of small amount onto a fundus of an eye by a reflected light from the fundus, and a wavefront detecting system for detecting a wavefront of luminous flux emitted from the interior of the pupil of the eye by a reflected light from the fundus, where the projection system projects a light source image of small amount onto a fundus of an eye, and the wavefront detection system detects the wavefront of luminous flux emitted from the interior of the fundus by a reflected light from the fundus, and a deflection prism having at least one transmission surface for aberration correction within both optical paths of the projecting system and the wavefront detecting system, can deflect the incident luminous flux.

Abstract: A non-contact type tonometer includes a compressed air blowing unit which compresses air in a cylinder by means of a piston disposed within the cylinder and blows the compressed air to a cornea of an examinee's eye; a driving unit which drives the piston; a pressure sensor which detects pressure of the air in the cylinder; an optical system which projects light to the cornea; a photosensor which detects, of the light projected by the optical system, reflection light reflected from the cornea; and a controller which obtains a change in pressure for a predetermined time based on a detection result by the pressure sensor when the photosensor detects a predetermined change amount of the reflection light after the driving unit drives the piston to start blowing of the compressed air to the cornea from the compressed air blowing unit, and changes a timing of stopping supply of driving power to the driving unit based on the obtained change in pressure.