Abstract: The invention consists of an eyetracker, a display driver, an adaptive display interface controller, and a digital computer. A user of the invention can operate a heads-up display (or a head mounted display) with an eyetracker, leaving his hands free to perform a manual control task. The user selects a display element from an array of choices on the heads-up display by gazing at an element while he activates a confirming mechanism. Both tasks share a common visual working area with overlaid visual images, and task interference is reduced since eye-movements and visual attention are dedicated to the same display surface.The adaptive display interface automatically aids the user in display operations during high manual task loading. The adaptive interface is driven by an electronic Expert System on human visual processes programmed as a Fuzzy Logic controller.