A head-up display system projects an image directly onto the human retina with low-energy lasers or LCDs. Head-up displays can give the user ' the illusion of viewing a typical screen-sized display hovering in the air several feet away. In principle the technology can provide full-color, highresolution dynamic displays, but in practice the components necessary to achieve the full potential of the technology are either highly expensive. ; Although the technology was invented by the University of Washington in the Human Interface Technology Lab (HIT) in 1991, development did not begin until 1993; the technology still needs much refinement and has only been commercialized in specialized sectors of the display market such as automobile repair and some parts of the military.

The head-up display is highly efficient with respect to power consumption, requiring far less power than the postage-stamp LCD screens used commonly in today's Head up Display mobile devices. A head-up display uses about a micro-watt of power. Since head-up display displays project images directly onto the retina, they provide a sharp, clear image regardless of external lighting conditions. Head-up displays require a fraction of the hardware of conventional display devices, allowing for lighter and more elegant mobile devices, in high demand for today's electronics market. Head-up display shows strong potential to replace LCD screens in cell phones, handheld computers, handheld gaming systems, and eventually even larger computers such as laptops.