Can I have astigmatism in both eyes?

Eye exam by optometrist
National Eye Institute, National Institutes of Health

Question: Can I have astigmatism in both eyes?

Answer: Astigmatism almost always occurs in both eyes. The condition can occur in only one eye but usually is the result of a physical injury. 

What Is Astigmatism?

Astigmatism is a fancy word that is used to describe a malfunction of the way vision works. Astigmatism is a disorder of the eyes that can cause light to focus on two points instead of just one.

This condition can be the result of a misshapen cornea. An astigmatism causes people to have blurry, slanted or distorted vision. It is a vision disorder in which the eye focuses light on the retina at two points instead of just one. People with astigmatism sometimes complain of blurred, distorted or slanted vision. Astigmatism almost always occurs in both eyes and is usually quite symmetrical between the two. Astigmatism in large amounts is often inherited. Astigmatism can occur in one eye but this is most often due to a traumatic injury.

What Causes Astigmatism?

Astigmatism is sometimes caused by an irregularly shaped cornea, the clear dome like structure on the front part of the eye. The cornea may have areas that are flatter or steeper than others, resulting in distorted vision. The crystalline lens inside the eye may also be tilted slightly, causing astigmatism. In addition, astigmatism can be caused by an irregular eyelid or heavy tissue pressing down on the eye.

Astigmatism is very common and usually treated or corrected by wearing glasses or contact lenses. Refractive surgery such as LASIK or astigmatic keratectomy can also be helpful in treating astigmatism.

What You Need to Know

Astigmatism, if left untreated, can cause distressing vision problems. If you have astigmatism, you may have symptoms to alert you or your doctor.

Some symptoms of astigmatism may occur alone, but some of the symptoms might occur together at the same time. If you notice any of the following symptoms, it make an appointment with your eye care specialist as soon as possible. (It is generally recommended to have a comprehensive eye exam once per year to ensure the best possible vision as well as prevent or uncover eye disease.)

  • Blurry or Distorted Vision

  • Eye Fatigue

  • Eyestrain

  • Headaches

  • Inability to read small print

  • Constant squinting of the eyes

Diagnosing and Treating Astigmatism

Your eye doctor may diagnose astigmatism by conducting a variety of tests. Some of the tests used to diagnose astigmatism include a simple vision test, light refraction test, cornea measurement, or electronically mapping the surface of the eye. 

Astigmatism is corrected by focusing light rays on a single plane. This can be accomplished by prescribing eye glasses or contacts, or be performing astigmatic keratotomy.

Sources:

American Optometric Association, Astigmatism. AOA.com, 2006-08.

Eskridge, J Boyd, Amos, John and Bartlett, Jimmy D. Clinical Procedures in Optometry. Copyright 1991, J.B. Lippincott Company.

Continue Reading