By Dr S.S. Gill
In our continuing series on Eye Health, Hospital Fatimah’s Consultant Eye Surgeon Dr S. S. GILL talks to us about EYE STRAIN.
WHAT IS EYE STRAIN?
The medical term for eye strain is asthenopia. When we say ‘Eye Strain’, it is actually describing a symptom of the eye. Eye strain occurs when your eyes get tired from intense use, such as reading, computer use or driving for extended periods. It basically stems from looking at something over a long period of time without adequate breaks in between. Even surgeons are not spared from eye strain if they perform surgery under a bright operating theatre light without adequate breaks.
WHAT CAUSES EYE STRAIN?
Symptoms of eye strain include blurring vision, headaches, irritated eyes, and occasionally doubling of the vision. Headaches may start from the periorbital area (area around the eyes) of the face because a person may unconsciously clench the muscles of their eyelids, face, temples, and jaws when concentrating. This may in turn trigger migraine headaches if you are one of those people who frequently suffer them. Eye stress is increasingly affecting more and more people these days. Eye stress is as much of a concern as any other illness of the body. It makes the eyes tired and you get drained of energy. We need to remember that the eyes are used constantly throughout the waking hours of a day for various tasks including even socialising!
RATE OF EYE BLINKING!
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.
DISTANT AND NEAR VISION
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. When looking at near objects for long periods, it causes a strain on the ciliary muscles which are the eye muscle responsible for near vision. In other words eye strain is caused by visually concentrating on one thing or on one distance for too long.
ACTIVITIES that may cause eye strain include:
Prolonged digital media use.
Reading for long hours.
Watching television for long periods.
Driving long distances without breaks.
Sewing and knitting for long hours.
ENVIRONMENTAL factors that can add to eye strain:
Poor ergonomic computer setup.
Glare and brightness.
Poor & uncorrected vision (refractive errors).
Make efforts to consciously try to reduce the strain on your eyes by watching out for these contributing factors.