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.
Industrial augmented reality
Although the origins of Augmented Reality dates from the 1960s, when Ivan Sutherland created the first head-mounted display  it did not gain strength until the early 1990s, when the David Mizell and Thomas Caudell developed the first industrial AR at Boeing. They used a head-mounted display (HMD) to superimpose a computer-generated diagram of the manufacturing process with a real-time world registration and the user's head position calculation. They coined the name Augmented Reality to this technology.
Contemporary several prototypes were proposed to demonstrate AR's application to manufacturing: a laser-printer maintenance application was proposed in 1993 by Steven K. Feiner and coauthors by introducing the concept of knowledge-based AR for maintenance assistance (KARMA). Whitaker Ross et al. proposed a system to display the name of the part pointed by the user in an engine.