1. A night vision system for a motor vehicle comprising: an infrared camera mounted on the vehicle for viewing a roadway scene in front of the vehicle and producing a video signal representing the thermal pattern of the scene; a head up display comprising a combiner in the field of view of a vehicle operator, a video display for emitting an image, and an aspheric mirror for reflecting the image onto the combiner for viewing by the operator as a virtual image; the video display being responsive to the video signal for displaying the thermal pattern as a visible image; and the video display and aspheric mirror together affording a one-to-one size ratio of the virtual image to the real roadway scene observed by the operator.