Virtual reality
The 1990s saw the first widespread commercial releases of consumer headsets. In 1991, Sega announced the Sega VR headset for arcade games and the Mega Drive console. It used LCD screens in the visor, stereo headphones, and inertial sensors that allowed the system to track and react to the movements of the user's head. In the same year, Virtuality launched and went on to become the first mass-produced, networked, multiplayer VR entertainment system. It was released in many countries, including a dedicated VR arcade at Embarcadero Center in San Francisco. Costing up to $73,000 per multi-pod Virtuality system, they featured headsets and exoskeleton gloves that gave one of the first "immersive" VR experiences. "Computer Gaming World" predicted "Affordable VR by 1994".
Virtual reality cue reactivity
Arguably the most important facet in making a virtual environment seem real is an appeal to sight. A virtual reality headset, incorporating a head-mounted display (HMD) is placed in front of the eyes of a patient like a pair of sunglasses, enabling for complete visual attention. A virtual environment is then displayed. A system of motion sensors tracks movement of the patient's head. If the patient tilts, or turns his head to view another part of the room, the environment adjusts accordingly. This allows for a more realistic experience by limiting restrictions of the head.