A non-contact device for tracking gaze in a human computer interface

This paper presents a novel design for a non-contact eye detection and gaze tracking device. It uses two cameras to maintain real-time tracking of a person's eye in the presence of head motion. Image analysis techniques are used to obtain accurate locations of the pupil and corneal reflections. All the computations are performed in software and the device only requires simple, compact optics and electronics attached to the user's computer. Three methods of estimating the user's point of gaze on a computer monitor are evaluated. The camera motion system is capable of tracking the user's eye in real-time (9 fps) in the presence of natural head movements as fast as 100°/s horizontally and 77°/s vertically. Experiments using synthetic images have shown its ability to track the location of the eye in an image to within 0.758 pixels horizontally and 0.492 pixels vertically. The system has also been tested with users with different eye colors and shapes, different ambient lighting conditions and the use of eyeglasses. A gaze accuracy of 2.9° was observed.