By Dr S.S. Gill
Ipoh Echo’s EYE HEALTH series continues with Consultant Eye Surgeon Dr S.S. GILL talking to us about TIRED EYES.
Tired eyes are probably the commonest eye problem these days. The term asthenopia is frequently used to describe a group of symptoms which are related to the use of the eyes. Asthenopia drains us and ultimately affects our well-being. We are all prone for asthenopia because the eyes are used constantly at work throughout the waking hours of our day for various tasks. Intense use such as driving a car for extended periods, reading, or working at the computer all can contribute to asthenopia.
The symptoms of tired eyes include blurring vision, headaches, eye discomfort and occasional transient doubling of vision brought on after intense concentration. Some people while performing visually intense tasks, may unconsciously clench the muscles of their eyelids, face, temples and jaws, only to develop discomfort or pain from use of those muscles.
The normal blink rate in human eyes is 16-20 per minute. 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 asthenopia or tiredness.
Humans have evolved biologically as hunters and gatherers with our vision developed mainly for seeing distance (farsighted). Thus, it is not surprising that our eye muscles (ciliary muscles) are most relaxed when we use our vision to look at distant objects. 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 digital devices. Maintaining a sitting posture for long periods of time is in fact unnatural for us. When doing prolonged near work, the ciliary muscles work hard which over time results in asthenopia.
Briefly, common activities that may cause eye strain include:
- Computer use and computer games
- Reading long hours
- Driving long distances
- Sewing and knitting
Environmental factors that can add to eye stress:
- Low-light Levels
- Improper lighting
- Poor ergonomic computer setup
- Low screen contrast levels
- Glare and brightness
Take note of these and avoid continuous near focussing for hours on end without breaks. Take breaks every 20 minutes by looking into the distance for 20 seconds.