Next time you find yourself sat in front of a computer, turn sideways so that you can see the screen out of the corner of your eye. Unless you're working with a particularly high quality monitor with a fast refresh rate, you will probably see the screen flickering. This, along with the inevitable glare from a reflective glass surface can lead to eyestrain, fatigue and headaches.

Monitors also emit a certain amount of radiation and discharge static electricity (try running your fingers over the screen after it has been on for a while) - the effects of which are still open to debate, but for many are often the cause of dry eyes and a smarting sensation after many hours of sustained work.

An EEC directive, to be legislated on by member countries before the beginning of next year, states that Visual Display Units (VDUs) must be free from reflections and glare, and produce screen images free of flicker and instability. Businesses are going to have to choose between buying new monitors or fitting filter screens - the latter being a far cheaper option.

A number of manufacturers have developed filter screens of one type or another, but it is very difficult to find any which will deal with the combined effects of glare, radiation and flicker. Recently, however, the US company, OCLI, launched a range of filters as part of their Professional Plus series which will do just that. Constructed from toughened glass with their own HEA (High Efficiency Anti reflecting) coating on the front surface and an electronically conductive version on the rear, they completely eliminate static electricity by the connection of a thin cable from the frame of the glass to a convenient equipment earthing point.

The HEA coatings also ensure that ambient light passing through the glass is greatly reduced, so limiting reflection, and also eliminating screen flicker and filtering out radiation.

There are various different models for flat and curved frames along with a universal version called The 'Multiguard' which flips down over the screen. Special models are also made for Macintosh screens which fit tightly around the front face of the monitor. GND, the UK distributors, are currently offering hefty discounts with prices around the £90 mark - inclusive of postage and packing and covered by a lifetime guarantee.

Having used one of these for some weeks now, I can honestly say that the results are staggering. No more headaches or dry eyes - symptoms which I had, in the past, put down to working long hours. How effective they will be for you is rather difficult to determine; it will depend on how prone your are to the ill-effects in the first place and, of course, how much time you regularly spend looking at a screen. But with technology seemingly pushing us further and further towards permanent residence in front of a VDU, an OCLI screen could, quite literally, be just what the doctor ordered.

Price : Profile (with rubber surround), £135.12 RRP; special offer to MT readers, £89.17. Multiguard (hinged model), £116.32 RRP; special offer to MT readers £82.07. All prices inclusive of VAT, p&p, cleaning fluid and cloth.

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