How much difference is there between the various technologies of screens now available? And when it comes specifically to computer use is there one that is more fit for purpose than the others? It would seem so, but the technology that drives the screen is not the only important issue to be aware of when it comes to choice of computer screens and their use.

We tend to assume a technology that supersedes another is by definition superior, but in the case of screen technology this is not the whole story. CRT screens have a very high contrast ration 20,000:1 or greater; this is much higher than modern LCDs or plasma displays. It was less the technology than the size of traditional CRT screens that made them redundant.

LCD is said to be the most appropriate technology on the market for computer use and gaming because it displays static images better and with full colour detail, no flicker and no screen burn-in. Moreover the number of pixels per square inch is typically higher than other display technologies.

In 1993 the Health and Safety (Display Screen Equipment) Regulations came into force seeking to protect the health of workers by reducing risks from VDU work. Their official advice states ?only a small proportion of VDU users actually suffer ill health as a result of their work. Where problems do occur they are generally caused by the way in which VDUs are being used, rather than the VDUs themselves. So problems can be avoided by good workplace and job design and by the way you use your VDU and workstation.?

When it comes to reading the screen advice includes:

?Adjust brightness and contrast controls on the screen to suit lighting conditions in the room

?Individual characters on the screen should be sharply focused and should not flicker or move

The Health and Safety Executive recommend that computer users ?make full use of the equipment provided, and adjust it to get the best from it and to avoid any potential health problems.? It is important to arrange a desk and VDU to avoid glare, or bright reflections on the screen. This will be easiest if neither you nor the screen is directly facing windows or bright lights. There are a number of products available that enable a VDU to be positioned at precisely the right height and angle to suit each user. A monitor arm (or ?swing arm? as they are sometimes known) can do just that: enable a screen to be swung from side to side or up and down to encourage frequently changing and flexible working positions.

So, it would seem that the pros of LCD technology outweigh the cons: other (even older) technologies may have some superior technological benefits but the size and lighter weight of these screens enable them to be used in a way that improves the comfort and even health of the user.