1. Virtual reality
System that enables one or more users to move and react in a computer-simulated environment.

2. Various types of devices allow users to sense and manipulate virtual objects much as they would real objects. This natural style of interaction gives participants the feeling of being immersed in the simulated world. Virtual worlds are created by mathematical models and computer programs.

3. Virtual reality systems use special interface devices to immerse users in a simulated world. This user is wearing a head-mounted display (HMD) and gloves. The image on the screen is the image the user sees on the screens inside the HMD.

4. Interface Devices
Virtual reality simulations differ from other computer simulations in that they require special interface devices that transmit the sights, sounds, and sensations of the simulated world to the user. These devices also record and send the speech and movements of the participants to the simulation program.

5. Interface Devices The HMD or the Head-Mounted Display
Using this information, a computer recalculates images of the virtual world—a slightly different view for each eye—to match the direction in which the user is looking, and displays these images on the HMD.

6. Interface Devices The haptic interface
Relays the sense of touch and other physical sensations in the virtual world, is the least developed and perhaps the most challenging to create. Currently, with the use of a glove and position tracker, the computer locates the user's hand and measures finger movements.

7. Development and Uses
In recent years, virtual-reality devices have improved dramatically as the result of various technological advances. Computers now are more powerful, have a higher memory capacity, are smaller, and cost less than in the past. These developments have made it possible for scientists to develop virtual-reality simulations.

8. Development and Uses
Therapists use VR to treat sufferers of child abuse
and people who are afraid of heights.
Muscular dystrophy patients can learn to use a
wheelchair through virtual reality.
Surgeons may use VR to plan and practice an
operation on a virtual patient rather than a real person.

9. Development and Uses
Architects could take clients on a virtual tour of
a new house before it was built.
VR could be used to train the operators of aircraft
and other complicated machinery.

10. Development and Uses
Network VR simulations could enable people in many
different locations to participate together in teleconferences,
virtual surgical operations, or simulated military training
exercises.