Light splashes out of the screen, hits an array of sensory cells in your retina, is converted into a series of electronic pulses that forms an image in your brain. A series of electronic pulses streams out of a computer, is converted into a swarm of electrons that hits a wall of phosphor on the inside of the screen, generating light. Both ends of this communication are electronic - and many people believe that the intermediate processes can be eliminated, or at least reduced.

Our senses are what keep us in touch with the world outside. Where that world includes others such as ourselves, human or machine, it has long been a fantasy to converse without the trappings of our usual sight, vision and touch. Some of this trans-sensory conversation is emerging from the realms of myth, magic and science fiction to a form of reality. Virtual reality, actually.

The problem with virtual reality (VR), apart from the enormous hype so dangerous to new technology that surrounds it, is its weight. Few people care to explore its uses - from playing Zap Those Virtually Realistic Aliens to performing microsurgery by remote control - while wearing clumsy headgear, goggles, gloves and other encumbrances that resemble spare parts from a cast-off space suit. The unnatural sense of such special clothing adds considerably to the 'virtuality' of this reality. And traditional miniaturization helps only up to a point.

Traditional miniaturization would still require, for instance, little TV screens for each eye; lots of position sensors all over finger and other joints; and something really complicated to simulate a rough or smooth surface. Of course you can forget smell and taste, the step- children of our virtual senses.

However, virtual reality researchers have realized that miniaturization can be increased if all these interfaces between two electronic signals are reduced. A good example of this is the laser-based screenless display. Instead of projecting an image on a little screen covering an eye, it shines a laser beam on the retina itself, scanning it fast enough across the optical receptors to fool the eye into seeing a complete image. Unlike a screen, this method can completely fill the field of vision, and also track eyeball movement as a bonus.

Somatosensory stimulation is tougher. Even a slight semblance of changing surfaces at your fingertips would require impossible materials capable of transforming shape and structure at a microscopic level. On the other hand touch is a sense that is relatively primitive and well understood - so an array of electrodes stimulating the nerve-endings beneath the skin to emulate cold roughness could be easier to create. Similar electronic stimulation is probably the only way to create virtual jasmine, for although the sense of smell is very poorly understood, it is harder to generate random perfumes on the fly than to transmit their electronic representations far up in your nose.

While the direct transmission of thought through electronic 'brain waves' will remain a magician's art rather than an everyday science for a long time to come, sensory communication with little or no real involvement of the external sense organs is a practical possibility. While such technology can make video-game players dream and shrink surgeons to the size of an eyeball, it could also bring the blind sight, as it brings the deaf hearing even today.