Patent ID: 7578593

Claim:
A method of monitoring an eye of a human subject based on a succession of digital images captured by an imaging device focused on the subject, comprising the steps of: (a) actively illuminating the subject from a first location that is offset from the imaging device and capturing a first image of the subject while so illuminated; (b) actively illuminating the subject from a second location that is offset from the imaging device and displaced from said first location, and capturing a second image of the subject while so illuminated; (c) processing said first image independent of said second image to detect and track the subject's eye; (d) processing the second image independent of said first image to detect and track the subject's eye; (e) repeating steps (a)-(d) if neither step (c) nor step (d) was successful; and (f) analyzing the detected eye to determine an eye state if at least one of step (c) and step (d) was successful.