Centre for Sight Africa How Glasses Correct Your Vision By Dr. I.G. Nathan

How Glasses Correct Your Vision By Dr. I.G. Nathan


Glasses are worn by millions of people worldwide to correct various types of refractive errors. The prevalent word used by eye doctors when prescribing glasses is that “the lenses will correct your refractive error.”

This is very reassuring, as it makes the patient know that there is a definite solution to their presenting complaint. However, it may also mislead some patients to think that the glasses will remove their refractive error permanently after a duration of use.

This expectation is exemplified by the fact that patients frequently ask “how long will I have to wear my glasses? Or say things like “I have been wearing my glasses for a long time. It hasn’t corrected my vision”. The latter is usually associated with patients dropping their glasses after a duration of use.

So what are refractive errors? And what does your eye doctor mean when he/she says you need glasses to correct them?

Before we go on to talk about what refractive errors are, let us take a brief walk into how the eyes work. The eyes work like a camera to help us see a clear image. And like a camera, it has powerful lenses (the cornea and the crystalline lens) which help to bend or refract light from an image being viewed to focus it correctly on the film (the retina). The light focused on the retina is then converted to electrical signals which are sent to the brain for processing into what is seen as a picture.

Refractive errors occur when the eye’s focusing system (the cornea and the crystalline lens) are unable to correctly focus light from an image being viewed onto the retina. This means that the image being seen will be blurred.

To help ensure the image your eyes are seeing are clear, your eye doctor places lenses in front of your eyes to help them correctly bend and focus light onto the retina. As long as the glass lens remains in front of the eyes, it will correctly focus light onto the retina. When the lens is removed, light is focused incorrectly.

So what the eye doctor means when he says your glasses will correct our vision, he means that as long as you are wearing the lenses, it will correctly focus light onto your retina. He doesn’t mean it will permanently alter the eyes shape or function to make it see clearly by itself.

So if the glasses will not correct my vision permanently, why do I need to wear them? Firstly wearing prescribed glasses helps you see clearer. It helps you appreciate colours, contrast better, and thus makes your visual experience and communicating with our environment better. This is particularly important for children in school, as it helps them see what is being transmitted to their brain via learning better, which helps them understand what is being communicated better, leading to better retention.

Secondly, some refractive errors may cause our eye muscles to do a lot of work trying to focus the image on the retina. This constant work being done by the eye muscles may make them tired frequently (causing an even more blurred vision), or cause aches in or around the eyes and head (headaches) or other eye discomfort. Wearing your glasses will make these muscles relax, and prevent the associated aches and discomfort.

Is it not possible to use drugs or other forms of therapy instead?

Vision is an optical task. Refractive errors are an optical problem, and they need an optical solution. So glasses and contact lenses are the only way they can be corrected. So even if your doctor gives you drugs supplements (like vitamin A, yeast or other derivatives) as part of a wider treatment regimen to make you see better, or manage side effects of refractive errors, or the effects of refractive errors (like eyestrain, headaches, etc.) glasses still remain the first line of action and the most important component in managing refractive errors.

So now you know how wearing your glasses can correct your vision.

We at the Centre For Sight Africa have trained eye doctors who will give you the best refraction you can get. Visit us today for an eye examination.

Leave a Comment

Your email address will not be published. Required fields are marked *