Abstract: A navigation system for a blind individual to guide the individual through a virtual environment, includes a transponder adapted to be carried by the individual, a tracking system for determining the position of said transponder within the virtual environment, and a feedback system coupled to said transponder to generate a non-visual sensory signal indicative of said position of said transponder. The transponder has a primary sensor direction that is aimed by the individual, and the non-visual sensory signal provides indications of virtual objects aligned with said primary sensor direction, whereby the individual may be guided to find or avoid virtual objects in said virtual environment.

Abstract: A system for tracking the 3D position and gaze angles of the eyes over their full range of movement in space relative to a camera or relative to the head without the need for calibration or specialized image aquisition equipment. The eyes are tracked on the basis of surface features in relation to a geometrical 3D model of the eyes by means of a standard consumer device for recording the sequence of face images in conjunction with computing capability. The resultant eye positions and pupil diameters are used to control the information on a viewing screen or in another device. The system further allows for deriving the angular trajectories of the eye movements and for fitting model functions of these trajectories to characterize the degree of normality and deviation from normality of the binocular eye movement parameters.