US Patent 6926429 Eye tracking/HUD system

In a preferred embodiment, an apparatus for eye tracking, including: an illuminator; reflection apparatus to reflect illumination from the illuminator onto a surface of a windshield of a vehicle in which the windshield is installed, such that the illumination is reflected onto at least an eye of a person in the vehicle, and to reflect an image of the at least an eye, and a sensor to receive a reflection of the image of the at least an eye reflected by the reflection apparatus and to produce an output signal representative thereof.