From the boardroom to the operating room, virtual reality's application s go far beyond mere games.
Last November, two researchers from the University of Washington blasted into space from Seattle, went into orbit and came back to earth in Tokyo. They went into a meeting room - Mount Fuji was in the background - where two Japanese were already sitting. At each corner of the table was a goal post, and the four people took part in a game to herd cows and sheep, bleating and mooing, into the goals.

This may sound like a bizarre dream, but it happened - sort of. The two sides did indeed play the game, but they never left their home cities. They met in a "virtual common" in an experiment designed to show how virtual reality can replace the physical world. This was a teleconference, 21st century-style.

Virtual reality is the creation of artificial "worlds" through powerful computer graphics. Users typically view them on tiny screens in front of their eyes - each image is slightly different, giving a three-dimensional effect and tricking people into believing that they are "inside" the computerised world. Sensors mean that when they turn their heads the view swivels, reinforcing the impression that the world is all around them.

By far the most widespread application of VR is games - where the third dimension can add terrifying reality - but it is increasingly recognised as a potentially serious tool. Much work, however, will have to be done to develop the technology beyond its current crude state before it gains widespread acceptance.

The Human Interface Technology (HIT) Lab was set up in 1989 at the University of Washington in Seattle to transform virtual concepts into saleable products. HIT Lab was formed by Tom Furness, a researcher with the US Air Force, who created a computer system in the mid-Eighties to help fighter pilots to overcome a huge problem - being overwhelmed by information during combat. Mr Furness developed a virtual cockpit that, through bulky headgear, created a synthetic but three-dimensional representation of the world outside the aircraft.

Now he is looking at ways of taking virtual reality further. One of his latest adventures is the GreenSpace Project, which created the virtual common. Working with the Fujitsu Research Institute, HIT Lab is trying to create virtual meetings in which participants not only see each other but also "feel" each other, by using a raft of visual, tactile and aural cues. But last year's experiment showed how limiting today's technology is - faces "hovered" in the meeting room, but a proposal to change their expressions to match speech patterns had to be abandoned.

The range of HIT Lab projects shows VR's vast potential. For example, Suzanne Weghorst and Jerry Prohero have been developing a radical new approach to the treatment of people with movement disorders. Many people with Parkinson's disease experience great difficulty in walking, a condition known as akinesia. Using goggles and other devices, the researchers have simulated an effect called kinesia paradoxa, the triggering of normal walking behaviour in akinetic Parkinson's patients by placing physical obstacles at their feet. When the patients see the obstacles, even though they are virtual, they correct their walking.

In the near future, these patients will not even have to wear bulky headgear. Current helmet display technology is based on colour LCDs. Each eye has its own small screen containing around 90,000 pixels - enough to give a reasonably but not terribly sharp image. HIT Lab is working with a company called Micro Vision on a way of projecting images by laser directly on to the retina.

The laser beam is modulated to match the intensity of the image being rendered and scanned to place each image point or pixel at the proper position on the retina. A horizontal scanner moves the beam to draw a row of pixels, and a vertical scanner then moves the beam to the next lines where another row of pixels is drawn. Not only is the resolution much better than a conventional display, but the system works in full daylight and is so small it can be can be mounted on ordinary glasses.

As research indicates, virtual reality can be an effective educational tool. HIT Lab has also launched its Virtual Reality Roving Vehicles (VRRV) program. In the tradition of the mobile library, it will bring VR technology to urban and rural schools via vans equipped with portable "world-building" systems. Students will be able to build their own 3-D worlds, which could be linked by broadband connections into a virtual common, giving students the chance to "meet" others and take part in experiments together.

Schoolchildren in the western US are already discovering the joys of virtual meetings. Whether they will take them for granted in their adult life depends largely on the progress made in establishments such as HIT Lab.