Virtual reality

Virtual reality is the use of computer-generated imagery and simulation to create an environment that a person can explore or affect. Many systems show a stereoscopic image in a head-mounted display and use sensors to track head or body movement, updating the view as the user moves. Controllers, hand tracking and haptic devices can let a user act on virtual objects or receive simulated touch. Other systems use surrounding screens or projection rooms rather than a headset.

Researchers often distinguish technological immersion from presence. Immersion describes how a system delivers sensory information and limits awareness of the physical surroundings; presence is the user's subjective feeling of being located in the virtual environment. A highly immersive system does not guarantee that every user will feel present, and definitions of VR vary across fields. In augmented reality, by contrast, digital content is added to a view of the physical world rather than replacing it with a largely computer-generated scene.

Virtual reality grew from efforts in art, display technology, computer graphics and simulation. In the 1960s, Morton Heilig's Sensorama explored a multisensory simulated experience, while Ivan Sutherland and other researchers developed early interactive graphics and head-mounted displays. These prototypes were expensive and technically limited, but established ideas that later systems developed further.

The term “virtual reality” was coined by computer scientist and engineer Jaron Lanier in 1987. A later wave of consumer interest followed the development of modern headsets: a 2022 literature review describes Palmer Luckey's Oculus prototype in 2012 and Facebook's acquisition of Oculus in 2014 as milestones in the growth of home VR devices.

VR is used for entertainment and social experiences, but it also allows people to practise tasks or inspect places and objects in a simulated setting. Flight, driving and industrial simulations can present repeatable scenarios that would be difficult, costly or dangerous to stage in the physical world. Designers and engineers can view and assess three-dimensional models before building physical prototypes; educators can present simulated settings that students could not easily visit. Researchers and health professionals also use VR in training, rehabilitation and therapy, though the benefits depend on the task and should be evaluated for each use.

NASA's Johnson Space Center Virtual Reality Lab is one specific example: it trains astronauts for spacewalk and robotics operations by simulating procedures and interactions with robotic equipment. This is a specialized training application, not evidence that every VR simulation transfers automatically to real-world performance.

VR systems differ in their visual quality, tracking, controls and degree of immersion. Headsets and computing equipment can be costly or physically uncomfortable, and differences between the user's sensed movement and the movement shown in a simulation can contribute to cybersickness. Symptoms may include nausea, dizziness, disorientation or eyestrain; susceptibility varies among people and experiences. Research reviews caution that presence and cybersickness have complex relationships and that results depend on system design and individual factors.

VR is therefore best understood as a set of tools, not as a single device or a substitute for every real-world experience. Its usefulness depends on whether the simulated environment, feedback and interaction are appropriate to the task, and on whether users can access and comfortably use the equipment.