Buy a computer and you can expect colour graphics, stereo surround sound and so much disc space it would be churlish to complain. But imagine telling the salesperson you not only want to see and hear what’s happening on screen, but you also want to experience it. When you move your mouse over a picture of some rocky terrain on a map, for example, you want to be able to feel the bumps.

Novel as it may seem, being able to feel your way round the screen could enable the visually impaired to use everyday computers. And surprisingly, a solution is close at hand. It’s a spin-off from “force feedback”, a feature that adds realism to many joystick and steering wheel-controlled computer games. This is the technology that allows you to feel the engine start when you drive a car in a racing game, or gives you a jolt when it crashes.

Now there’s a force feedback desktop mouse. Created by keyboard and mouse manufacturer Logitech, it lets you feel your way round a Windows program. You can feel the sliders and button edges, have your hand gently pulled towards a window border, and experience a springy sensation as you pull the window open. You can feel your way around the Web, too, bumping over the hyperlinks and check boxes on every page. Uncanny notions like “big files are heavier and seem harder to move”, or “protected files are stuck to the Windows folder”, make you realise what’s missing from this unfeeling computer world.

Dr Louis Rosenberg of California-based Immersion Technology is an expert on haptics, the science of human touch. His company is keen to bring sensation into computing. He says that there are two sides to his “TouchSense” technology. “First there’s the perceptual side,” he explains, “where you can feel everything the mouse interacts with. When the cursor hits the surface you can feel its texture. When you stretch something you can feel it pulling. The second part is improving your performance. In the real world you have a sense of touch not just to understand your surroundings, but to manipulate them.”

The perceptual side would interest anyone developing software for teaching. Simulations, for example, illustrating friction, inertia, gravity or the forces holding atoms together would be able to make teir teaching points very easily. Similarly, for geography, say, the contours on a map can be translated into the hills and bumps they represent and force fed back to the student.

We tested Rosenberg’s claim to offer improved mouse performance. With the help of the force feedback mouse you will find the cursor physically drawn to targets and buttons on screen. We found that hitting cities on a map improved by 80 per cent when we could feel the cursor. So for those with neuromotor disabilities who find it hard to use a mouse due to a hand tremor, the improvement in their targeting of on-screen icons is dramatic.

If this technology offers an interesting aid to older people, where ageing has degraded their mouse agility, the benefits to the visually impaired seem extremely promising. Immersion has been experimenting with a system that combines touch feedback with voice prompts. Here a voice speaks menu items as you move the cursor up and down it. “We found people who are blind could navigate Windows,” says Rosenberg. “and could find their way round the Net. We believe this is the technological path that will make the Internet accessible to them.”

It’s highly likely being able to touch things on screen will take off in a big way, driven not just by games manufacturers, but by the current growth of Internet shopping. Traders wanting to enhance their offerings, to let people feel the goods they are interesting in buying, or try them out can now offer shoppers mind-boggling opportunities to feel, drag and drop their merchandise. And then there are those wanting to cater for visually impaired shoppers or online learners, who cannot get around as easily as everyone else.

With the mouse costing pound;80, none of this ought to be too far away. Immersion has released a free kit of tools to encourage those wanting to develop applications of the technology. You can use the TouchSense software development kit to associate a texture sensation to a mouse action on screen. The kit has a library of sensation files that a developer can use much like a clip art library.

Next time you’re in a computer shop, look out for the force-feedback mouse. It is possible that one day, just like graphics, speakers and modems, you won’t want to buy a computer without one.

Logitech www.logitech.com

Immersion www.immersion.com