The Guide Dogs for the Blind Association has unveiled its free online computer eye test for regular users of VDU today. The launch took place at the House of Commons, making MPs the first users to check their eyesight online.

According to the London Hazards Centre, a massive 70 percent of people working with VDUs for more than six hours a day experience visual problems.

But the Guide Dogs Association's own research found nearly half of users (43 percent) had not had an eye test in the last year, which was especially common in men who do not wear glasses or contact lenses. A third (31 percent) admitted they had not seen an optician in the last five years.

"We hope that by working on fun and informative projects we can push eye care to the top of the health agenda," said Geraldine Peacock, Guide Dogs' chief executive.

However, the Royal National Institute for the Blind stressed that there is no evidence that using VDUs causes blindness or serious sight loss.

"Certainly looking at a computer can make your eyes tired, but there is no evidence that it can cause blindness," said Joe Korner, communications manager at RNIB, "which is why regular health and safety advises people to take frequent breaks and to try to limit daily use to four hours."

Under the Health and Safety (Display Screen Equipment) Regulations 1992 people who use a VDU as part of their job are entitled to one free eye test per year, plus money towards glasses if they are required.

But whose responsibility it is to ensure these eye tests are carried out is debatable.

"I'm not really sure whose fault it is. It's one of those health issues which individuals as well as employers should be aware of," said RNIB's Joe Korner.

Although the Guide Dogs' quick eye test is a useful check, it is not a replacement for a trip to the optician.

"Only a full eye test with an optometrist can test for potentially blinding eye conditions. The RNIB recommends people should have an eye test at least every two years," added Korner.