Eye tracking systems and methods

Abstract

Methods and systems for tracking an individual's eye, by tracking one or more ocular axes, are presented. The technique comprises the following: (i) illuminating the eye, over an area of the cornea extending over the pupil, with first and second incident light beams having a transverse cross sectional area smaller than a predetermined value with respect to an area of the pupil and propagating coaxially along a first optical path defined by central axes of the first and second incident light beams, wherein said first incident light beam is configured to be reflected from the cornea and said second incident light beam is configured to pass through the cornea and the pupil and to be reflected from a retina region of the eye; (ii) detecting respective first and second reflected light beams; (iii) adjusting the first optical path such that said first reflected light beam propagates along said first optical path and said second reflected light beam propagates along a second optical path having a predetermined spatial relationship with said first optical path whereby said predetermined spatial relationship is indicative of said ocular axis being along at least said first optical path; and (iv) tracking said ocular axis of the eye under changes in gaze direction of said eye by repeating (i) to (iii).