Astigmatism – a long, hard to pronounce word that strikes fear to the faces of patients every day. Follow up questions include, “Am I going to go blind?”
Rest assured, astigmatism is not a disease or pathology, it is simply a condition that causes blurry vision quite similar to nearsightedness or farsightedness. In fact, astigmatism to some degree is extremely common. Slight amounts of astigmatism may not even affect your vision, but larger amounts can cause distortion, blurry vision, eyestrain or headaches.
Technically, astigmatism is when your eye has two different focal points, thus preventing a sharp image from being focused on the back of your eye. This most often results from your cornea, the clear part in the front of your eye, not being perfectly round.
The example we often use is to relate your cornea to the shape of a football rather than a basketball. When light rays enter your eye from different directions, they are focused in different places. And because your eye cannot focus what you’re look at into a single point, your vision is blurry at all distances.
There is usually no specific cause of astigmatism, although genetics certainly can be a factor. Most people have it from birth. Other ways astigmatism may develop is from the lens inside your eye not being round, from an eye injury or from an eye disease.
One such disease is keratoconus, where the cornea becomes progressively thinner and cone shaped. Early keratoconus causes symptoms of astigmatism, which can progress to severe astigmatism requiring special contact lenses or possibly a corneal transplant.
Astigmatism can be detected with a comprehensive eye examination from your Optometrist. The tests are the same as any complete exam – we check your visual acuity, the curvature of the front of your eye, and what prescription lenses you may need to see better. All of this information together helps to determine if you have astigmatism and to what degree, as well as any correction to help you see your clearest.
Astigmatism is a common and easily correctable condition affecting millions of people. You shouldn’t fear the diagnosis, you should only correct your vision and check your eye health to ensure your are seeing at your optimum level.