There is technology available that allows a user to interact with a computer-simulated environment; rather it is a real or imagined one. These visual experiences can be displayed on a computer screen or through stereoscopic displays. Some displays include sound and/or tactical information known as force feedback.
Virtual Reality simulation is also used in simulating combat and pilot real world situations for the purpose of training, as well as for computer games.
Michael Heim's book 'The Metaphysics of virtual Reality' identifies seven different concepts of virtual reality: simulation, interaction, artificiality, immersion, telepresence, full-body immersion, and network communication.
In the future, graphics displayed in the HMD will soon reach a point of near realism, with audio sounds moving into three dimensional sounds. There are attempts right now at simulating smell. The purpose of current research has been linked to a project that is aimed at treating Post Traumatic Stress Syndrome. The treatment entails exposing the patient to combat simulations, complete with smell, therefore, taking Virtual Reality into the therapeutic arena.
Sony has received a patent for the idea of a non-invasive beaming of different frequencies and patterns of ultrasonic waves directly into the brain to recreate all five senses. There has been research to show that this is possible.
Famed inventor/futurologist Ray Kurzweil claims that within the next 20 years, machines will achieve human-like intelligence, we will have the option of having tiny robots transplanted into our brains to increase our intelligence, every part of our bodies will have artificial counterparts that will help us to live longer, and virtual reality will compete with 'ordinary reality' as a viable alternative.