An electronic device that allows a person to control a computer by looking at words or commands on a video screen.

A very low intensity light shines into one of the user's eyes. Reflections from the cornea and retina are picked up by a television camera.

As the direction of the person's gaze moves, the relative position of the two reflections changes, and the computer uses this information to determine th area at which the person is looking. The computer then executes the command.