Eye Health with Consultant Ophthalmologist, Dr. S.S. Gill – Part 1


Dr. S.S. Gill

What is eye strain?

The term EYE STRAIN is frequently used to describe a group of symptoms which are related to use of the eyes. Eye strain is a symptom, not an eye disease. Eye strain occurs when your eyes get tired from intense use, such as driving a car for extended periods, reading, or working at the computer. If you have any eye discomfort caused by looking at something for a long time, you can call it eye strain.

What causes eye strain?

The medical term for eye strain is asthenopia. The symptoms of ocular fatigue, tired eyes, blurring vision, headaches, irritated eyes, and occasionally doubling of the vision are brought on by concentrated use of the eyes for visual tasks. Some people, while concentrating on visually intense tasks, unconsciously clench the muscles of their eyelids, face, temples, and jaws and develop discomfort or pain from use of those muscles.

Eye stress affects a large majority of the population. After all, our eyes are constantly at work.  Eye stress is as much a concern as any other illness of the body. It makes the eyes tired and you drained of energy. Eye stress actually affects our well being because the eyes are used constantly at work throughout the waking hours of a day for various tasks including even socialising!

The normal blink rate in human eyes is 16–20 per minute. Studies have shown that the blink rate decreases to as low as 6–8 blinks per minute for persons working on something that requires concentration like looking at the computer screen. This leads to dry eyes which can further worsen the situation.

It is interesting to note that humans evolved biologically as hunters and gatherers. This means that our vision was developed primarily for seeing distance (98% of all humans are born farsighted). Our eye muscles (ciliary muscles) are at their most relaxed state when we use our vision to look at distant objects and large spaces. In a similar fashion, our bodies were designed for movement but we are becoming creatures who spend more and more time indoors behind desks, and so maintaining a sitting posture for long periods of time is actually unnatural for us. All of this adds to interlinked element of eye and physical strain.

Most commonly, eye strain is caused by straining ciliary muscles which are the eye muscle responsible for near vision. Typically these muscles are strained by keeping it in one position for a long time. In other words eye strain is caused by visually concentrating on one thing or on one distance for too long.

Therefore, it would be good to remember that the eyes tend to strain faster when focusing on near distances as opposed to far distances.

Briefly, common activities that may cause eye strain include: computer use and computer games; reading long hours; watching television for long periods; driving long distances; sewing & knitting.

Environmental factors that can add to eye stress include low light levels, improper lighting; poor ergonomic computer setup; low screen contrast levels; glare and brightness.

Personal factors that may contribute to eye strain are poor & uncorrected vision (refractive errors), physical stress, fatigue and tiredness, poor posture and alcohol and drug use.

There are many ways to prevent eye strain. Consciously try to reduce the strain on your eyes while you are actively using them. Try to figure out what element of the fatiguing activity is causing the problem and reduce it.

For more information, contact Gill Eye Specialist Centre at 05-5455582 or email: gilleyecentre@dr.com.