Alcon Inc.
SYSTEM AND METHODS FOR IDENTIFICATION OF THE HUMAN VISUAL AXIS

Abstract:

The present disclosure generally relates to methods and apparatus for accurate identification of the visual axis of the eye. In one embodiment, a visual axis identification system includes a fixation light source, a camera, a processing system, and a multifocal lens. The patient focuses their gaze through the multifocal lens and onto a fixation light beam provided by the fixation light source. The passage of the fixation light beam through the multifocal lens creates two or more images on or near to the patient's retina. The multifocal lens and/or the patient's eye are then moved relative to each other while the patient continuously maintains their gaze on the fixation light beam. The patient's visual axis may be located by determining the location of the optical center of the multifocal trial lens relative to the patient's eye when the centers of the multiple images coincide on the retina.