"The most common cause of eye strain with visual display units (VDUs) [computer screens] is a bad workstation set-up, " says Kevin Culliton, honorary secretary of the Association of Optometrists Ireland.

"Another is the detail and visual clarity needed to do a job. For example, financial workers may need to see minute figures on the screen and so are putting their eyes under more strain than a regular VDU user would.

"It's important employers conform to health and safety legislation in this regard; it's in the interest of everyone.

It's also vital employees are aware of their rights and ensure they take the opportunity to get an eye screening at the employer's expense if they are worried about strain.

They are also entitled to the price of a basic pair of glasses, if needed solely for use at a VDU, " he adds.

Ian McLeish, an optometrist at McGivney's Opticians in Dublin, says that if an employee feels eye discomfort, they should go for a screening.

"Often, we find computer users simply do not blink enough and this causes the majority of eye dryness or strain, " says McLeish. "At the end of a day, a computer user's eyes may feel pink and gritty and he or she may assume this is eye strain. In fact, this is only eye dryness and it can be combated by blinking and looking away from the VDU."

McLeish's advice to employees is to take as many breaks as they can from their computer screens. "Even if an employee just makes a phone call or walks to the printer to pick up a page, this will benefit their eyes as they will blink more again, " he says.

But computers alone get too much blame for causing eye problems. "People who experience eye problems after constant computer work would be prone to these anyhow, " he says. Eye dryness and eye strain won't usually cause any major longterm damage, but people should get an eye check every two years.

Lighting and reflections can also cause eye strain. "A screen should never face a window or have a window behind it. However, in practical terms this is impossible to enforce, " he explains.

Fluorescent lighting found in offices built for workers who looked at paper files all day is often not bright enough for employees who use computers.

A GLANCE AT BENEFITS If you have eye problems that are not just caused by looking at a computer screen, your employer is not obliged to pay for your glasses or contact lenses.

However, if you have enough PRSI contributions, you may still qualify for optical bene"t. This entitles you to a free sight test (it's worth noting that a sight test for computer screens or driving licence are not covered under the scheme), a "xed amount towards an eye exam for contact lenses, free basic glasses or a "xed amount towards other glasses, replacement lenses for existing frames and a "xed amount towards contact lenses.

To "nd out if you are eligible, you need to "ll out a copy of Form O2, available from your local social welfare services of"ce or the treatment bene"t section of the Department of Social and Family Affairs. Call 1890 400400 (ext 4480) for further details.

EMPLOYERS' DUTIES According to the Safety, Health and Welfare at Work (General Application) Regulations, 1993, there is a range of measures that employers must take to safeguard workers using computers.

This includes:

- ensuring the lighting, reflection and glare of the employee's workstation is adequate and suitable;

- allowing the employee adequate breaks away from his or her workstation;

- most importantly, organising and paying for eye screening or tests if an employee feels his or her eyesight is being affected by computer work;

- if spectacles are required for use at a screen, the employer must pay for basic prescription glasses or give the worker money towards buying glasses.