Ivan Sutherland's 1968 ground-breaking AR prototype was actually called "the head-mounted display", which is perhaps the first recorded use of the term "HMD", and he preferred "Stereoscopic-Television Apparatus for Individual Use.
[3] This prototype was created in 1968 by computer scientist Ivan Sutherland with the help of his students Bob Sproull, Quintin Foster, and Danny Cohen.
At MIT's Lincoln Laboratory beginning in 1966, Sutherland and his colleagues performed what are widely believed to be the first experiments with head-mounted displays of different kinds.
The device was primitive both in terms of user interface and realism, and the graphics comprising the virtual environment were simple wireframe rooms.
The HMD had to be attached to a mechanical arm suspended from the ceiling of the lab partially due to its weight, and primarily to track head movements via linkages.
The system itself consisted of six subsystems: a clipping divider, matrix multiplier, vector generator, headset, head-position sensor, and a general-purpose computer – which would make these the components of the first virtual reality machine as we know them today.