Virtual reality
Around the same time, Douglas Engelbart used computer screens both as input and output devices. In 1968, Ivan Sutherland, with the help of many students including Bob Sproull, created what was widely considered to be the first head-mounted display (HMD) system for use in immersive simulation applications. It was primitive both in terms of user interface and realism, and the HMD to be worn by the user was so heavy that it had to be suspended from the ceiling. The graphics comprising the virtual environment were simple wire-frame model rooms. The formidable appearance of the device inspired its name, The Sword of Damocles.
Applications of virtual reality
Thomas A. Furness III was one of the first to develop the use of VR for military training when, in 1982, he presented the United States Air Force with a working model of his virtual flight simulator the Visually Coupled Airborne Systems Simulator (VCASS). The second phase of his project, which he called the "Super Cockpit", was even more advanced, with high-resolution graphics (for the time) and a responsive display. Furness is often credited as a pioneer in virtual reality for this research. The Ministry of Defense in the United Kingdom has been using VR in military training since the 1980s. The United States military announced the Dismounted Soldier Training System in 2012. It was cited as the first fully immersive military VR training system.