A mouth-operated computer input device includes a mouthpiece to be positioned in a user's mouth, and an optical device carried by the mouthpiece for emitting light from a surface area thereof. The optical device controls movement of a cursor on a computer display based upon movement of the user's tongue across the surface area. The optical device includes a light emitting device for emitting the light, and a sensor adjacent the light emitting device for sensing the light reflected from the user's tongue. A processor calculates movement of the user's tongue based upon the light reflected therefrom.