Virtual reality is "a system that creates an artificial three-dimensional (3D) world where the communication is interactive with immediate response" or "a computer-generated environment in which the user is able to both view and manipulate the contents of the environment."

Benefits of Virtual Reality Technology
There are a number of advantages in using VR technology in a number of business areas. For instance in the automotive industry, prototypes can be built as virtual worlds rather than building real mock-ups.
This means having to build fewer real physical prototypes, which in turn means cost savings. Virtual prototypes are generally more flexible, leading to shortened lead time and other competitive advantages. The flexibility also enables designers to try more options before turning to production, leading to increased quality and increased customer satisfaction.
Other areas where VR is used extensively today is in training; environments that may be hazardous in the real world can easily be simulated using VR technology. Also, using VR makes it possible to go to places that are otherwise impossible to visit, such as a building that has not yet been build. For such applications an immediate understanding and holistic view can be achieved before having to experience the real world objects, e.g., NASA trained astronauts in virtual environments prior to the repair of the Hubble Space Telescope.

Simulator Sickness in Virtual Environments
Eugenia M. Kolasinski, U.S. Army Research Institute
Simulator Systems Research Unit, Stephen L. Goldberg, Chief
Training Systems Research Division , Jack H. Hiller, Director
U.S. Army Research Institute for the Behavioral and Social Sciences, 5001 Eisenhower Avenue, Alexandria, Virginia 22333-5600
Office, Deputy Chief of Staff for Personnel, Department of the Army
May 1995

Army Project Number 2O262785A791 — Education and Training Technology
Approved for public release; distribution is unlimited.

Findings:
Although there is debate as to the exact cause or causes of simulator sickness, a primary suspected cause is inconsistent information about body orientation and motion received by the different senses, known as the cue conflict theory. For example, the visual system may perceive that the body is moving rapidly, while the vestibular system perceives that the body is stationary. Inconsistent, non-natural information within a single sense has also been prominent among suggested causes.

Although a large contingent of researchers believe the cue conflict theory explains simulator sickness, an alternative theory was reviewed as well. Forty factors shown or believed to influence the occurrence or severity of simulator sickness were identified. Future research is proposed.