What Eyeglasses Can and Cannot Fix?

By admin | Oct 30, 2018

How do eyeglasses work?

Eyeglasses work by helping focus the light onto the retina. Our eye works just like a camera.  The front of the eye – the tear film, cornea, and lens – all work to focus light. This light is focused onto the retina, the film of the camera.  The image is finally developed in the brain.

If light rays are not focused sharply onto the retina, the image is blurry. Glasses help focus the light rays properly, thereby allowing us to see clearly.

How come my eye glass prescription changes with time?

When we are young, the eye continues to grow. This can cause changes in the eye glass prescription. As we become older, most eyeglass prescription changes happen due to changes in the lens of our eye. Our natural lens flattens and rounds up, thereby allowing us to see both at distance and near. Imagine how many times the lens does this in each day to allow you to see clearly! Over time, the lens becomes thicker and more opaque.  As a result of these normal aging changes, several things happen. In your 40s, it is common to need reading glasses to do up close work. Then, as the lens continues to change, it scatters light, resulting in a blurry vision. Glasses are needed to re-focus the light so that it is once again sharply focused onto the retina. Over time however, the lens becomes so opaque that it is like a dirty window – no amount of glasses correction will improve the vision further. This is when patients can consider cataract surgery.

What is astigmatism?

Generally, for the eye to focus light properly, the cornea needs to be a smooth spherical shape.  Sometimes, instead of being a smooth sphere, the cornea is an irregular shape like a football. This causes light to be improperly focused onto the retina, resulting in blurry vision. Astigmatism can usually be fixed using glasses or contact lenses.

Can glasses always correct my vision back to 20/20?

No, glasses cannot always correct your vision. Remember, all glasses can do is help focus light.  Therefore, if there is a problem with a dense cataract, it will be like a dirty window, and light cannot be properly focused. If there are diseases that affect the retina such as macular degeneration or diabetes, the film of the camera gets affected. If the film of the camera is affected, the resulting vision will be blurry no matter how sharply the light is focused onto the retina. It is important to realize that glasses cannot fix all visual problems. Here at Retina Consultants of Boston, we will take the time to explain your vision issue fully to you and offer the best options to care for your vision.