The Sword of Damocles is widely considered[by whom?] to be the first virtual reality (VR) head-mounted display (HMD) system. It was created in 1968 by computer scientist Ivan Sutherland with the help of his student Bob Sproull. Before he began working toward what he termed "the ultimate display", Ivan Sutherland was already well respected for his accomplishments in computer graphics (see Sketchpad). At MIT's Lincoln Laboratory beginning in 1966, Sutherland and his colleagues performed what is widely believed to be the first experiments with head-mounted displays of different kinds.
When Sutherland moved to the University of Utah in the late 1960s, work on integrating the various components into a single HMD system was begun. By the end of the decade, the first fully functional integrated HMD system was operational. The first display application was a cube suspended in the air in front of the user. 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. The unit was partially see-through, so the users were not completely cut off from their surroundings. This translucence combined with the other features in their infancy is why the system is often cited as a precursor to augmented reality technology as well.
Kalawsky contends that the first HMD fieldwork was conducted by Philco in 1961. Their system used a head mounted display to monitor conditions in another room, using magnetic tracking to monitor the user's head movements. The Philco HMD displayed actual video from a remotely mounted camera. The position of the camera was moved according to the tracked head movements, creating a sense of telepresence.