Non-invasive eye-gaze position detecting method used on man/machine interface for the disabled

A novel eye-gaze detection method overcoming the weaknesses of previous methods is proposed. This system utilizes a video-based technique. The eye, illuminated by low-level infrared (IR) light, is scanned by a charge-coupled device (CCD) camera with an IR pass filter. IR light enters the pupil, is reflected off the retina and comes out through the pupil. The pupil image appears as a larger half-lighted disc against a darker background, called the bright eye. Its position moves in the camera field, following the motion of the eye. A fraction of the IR light is reflected off the corneal surface. This appears in the camera field as a small, intense area called the glint. The method does not need any sensors attached to the user´s face, and allows free head movement