Computerisation of workplaces has led to improved productivity, information retrieval and access, but it has also placed increased strain on our vision.
The use of a computer screen involves concentration on a task usually less than 60 centimetres away. Ability to see clearly at these distances requires an unconscious effort. Part of this effort is sustained by focusing muscles that are inside the eye. The muscles change the shape of the eye's lens to focus sharply & clearly. The other part of the effort is neutralised by external eye muscles that turn the eye inward, coordinating eye movements & moving eyes quickly from one place to another.
Headaches, blurred vision, tired eyes & slow refocusing are frequent complaints made by users. In extreme cases flickering sensation, double vision and loss of concentration may also occur.
Undetected focusing problems are also a frequent cause of computer related eyestrain:
- Long sightedness (eye condition) - difficulty maintaining clarity on near objects.
- Astigmatism (eye condition) - blurred vision at all distances caused by the front surface of the eye being oval and not round.
- Presbyopia (age related condition) - prevents comfortable focusing on near objects due to hardening of the lens inside the eye.
- Apart from thorough diagnosis and management of any eye conditions by your optometrist, eyestrain can be reduced by using the following tips:
- Sit so that the top of the computer screen is below the straight-ahead seeing position.
- Avoid frequent changes in focus by placing your screen, keyboard and reference material at the same distance from your eyes.
- Set screens no more than three to four times brighter than the ambient lighting.
- Use a high degree of contrast between the characters on the screen and the background.
- Minimise reflected glare on screens.
- Do not sit facing an unshaded window or bright lights.
- Regular breaks may also reduce computer-related eyestrain.
When having your eyes tested, mention that you use a computer. Your optometrist will utilise specific testing procedures, and advise you on ways to make computer use more comfortable.