What causes short sightedness?

Myopia or short-sightedness is a vision problem that prevents the eye from focussing on distant objects, making them appear blurred.

How the eye sees

When you look at an object, light rays are reflected from it into your eye. The light passes through the cornea at the outer eye, through the lens and then onto the retina, the ‘screen’ at the eye’s rear. In a healthy eye the cornea and lens focus the light rays onto a small, specific area of the retina, allowing you to see a clear image of the object.

What happens with myopia?

With myopia, the eye is unable to focus the light properly onto the right part of the retina, preventing a clear image from being projected. Objects up close can still be seen as they reflect light at a more acute angle which is focussed onto the retina properly.

Causes of short sightedness

Myopia can be the result of several problems – it can be a weakness in the muscles that control the lens, the curvature of the cornea or the shape of the eyeball.

There is a genetic link to short-sightedness – if your parents are myopic, you’re more likely to develop it too and if one parent is myopic, you’ve a one in three chance of the same.

Babies born prematurely and who are underweight at birth are more likely to develop short-sightedness.

There is increasing evidence indicating that the way you use your eyes as a child and young adult will affect your future sight. Children and young adults who do lots of close-up work reading and using a computer are more likely to develop myopia. Similarly, research shows that people in professions that require extensive reading are more likely to be short-sighted.

Diagnosing myopia

If you find it’s a strain to see long distance, you should visit an optician to have your eyes tested. It’s important to have regular eye tests – besides diagnosing irreversible Vision Problems early; an eye test can also reveal serious conditions such as diabetes or high blood pressure. If you have known sight problems or illness that affects your vision, you should go for more frequent eye tests.

Treating short-sightedness

The most convenient correction for myopia is glasses. If you’re only mildly short-sighted you may only need these when you’re reading or driving.

Contact lenses are a great alternative if you feel self-conscious wearing glasses or for sport. However, you need to be comfortable touching your eyes to use them.

Different kinds of surgery are available to Correct Myopia too, though these are more expensive and intrusive. For example, laser refractive surgery has become more popular. Here, tissue is removed from the cornea, flattening it and so helping the eye to focus light. Another option is intraocular lens insertion. Here, an artificial lens is inserted in front of your own. However, this is a relatively new treatment and it is generally recommended for those unable to wear glasses or with Severe Myopia.

About the Author

Penelope Byrd is a freelance journalist specialising in vision care.

At Last! Amazing Discovery! See Without Glasses!

Spectacles: Their uses and abuses in long and short sightedness; and the pathological conditions resulting from their irrational employment This is a reproduction of a book published before 1923. This book may have occasional imperfections such as missing or blurred pages, poor pictures, errant marks, etc. that were either part of the original artifact, or were introduced by the scanning process. We believe this work is culturally important, and despite the imperfections, have elected to bring it back into print as part of our continu…