Carl Zeiss Meditec Gmbh

Göran Anders Johansson

Vincent Michael Patella

Harihar Narasimha-Iyer

Matthew J Everett

Christopher J R V Baker

Thomas K Fitzmorris

Methods for improving gaze tracking are presented. These methods eliminate the need for a separate initial calibration step to determine whether the subject is properly centrally fixated during testing. In one embodiment, whether the subject is centrally fixated is determined by identifying inlier and outlier gaze descriptors; the inliers are assumed to be associated with central fixation. This reduces the total time required for testing. These methods also improve the accuracy of gaze tracking during testing without the need for individual subject calibration. Instead, a database of reference eyes is used. The subject's eye can be compared to the reference eyes, and the mapping function for one or more reference matches can be used to estimate the subject's gaze direction. In another embodiment, previous calibration data from the same subject can be used to determine whether the subject is properly centrally fixated and/or the direction of the subject's gaze.

Systems and methods for improved ease and accuracy of gaze tracking

Systems and methods for improving the reliability of visual field test results are presented. In one embodiment, images of the eye are recorded during the presentation of visual stimuli and are displayed to the user to provide information on eye motion, eye position relative to trial lens, and eyelid closure during the test. Individual or combined images can be displayed for individual stimuli, specific test points, or points in the gaze trace in various embodiments of the invention.

Systems and methods for improved visual field testing

Systems and methods for providing variable refractive correction in a visual field testing device are presented. One embodiment of the variable refractive correction involves two or more aligned transmissive plates arranged to produce changes in refractive power by translation or rotation of the plates relative to each other. Several alternative designs for providing variable refractive correction are described. The refractive correction can be set manually or automatically based on knowledge of the refractive error of a specific patient and spherical and cylindrical refractive correction are possible. Additional lens systems can be used to extend the range of refractive correction to accommodate a larger patient population.

Systems and methods for refractive correction in visual field testing

Embodiments of the present invention include approaches for controlling light valve devices to improve the range and precision of the contrast ratio and the grayscale levels of a display used for visual field tests. In one embodiment, two or more illumination devices are used to enable the display device to display a wide range of contrast stimuli at precise illumination intensities over a fixed background illumination level. In another embodiment, the gamma curves of the display elements are adjusted to allow greater variations in the brightness of the display.

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San Francisco, CA, United States of America

Göran Anders Johansson