The document provides a history of the development of virtual reality technologies from the 1800s to present day. It discusses early concepts and inventions related to stereoscopic vision, virtual environments, and head-mounted displays. Key developments discussed include the Sensorama machine (1956), Telesphere Mask (1960), Headsight (1961), Sword of Damocles (1968), VIDEOPLACE (1975), Sayre Gloves (1982), DataGlove and EyePhone by VPL Research Inc. (1985), Virtuality arcade machines (1991), Virtual Vietnam PTSD therapy (1997), and Oculus Rift (2010). The document traces how VR has evolved from early concepts to commercial applications today.