The earliest applications of augmented reality were almost certainly the “heads-up-displays” (HUDs) used in military airplanes and tanks, in which instrument panel-type information is projected onto the same cockpit canopy or viewfinder through which a crew member sees the external surroundings.
Faster computer processors have made it feasible to combine such data displays with real-time video. Augmented reality applications also have been developed for smartphones and to a number of smart glasses to display information.
Due to encumbered control, Smart Glasses are primarily designed for micro-interaction like reading a text message. Such information may be supplied using some kind of positioning system to provide location dependent information.