Diseases & Conditions

Astigmatism


Overview, Causes, & Risk Factors

An astigmatism is an abnormal curve in the optical part of the eye that produces a blurred image.

What is going on in the body?

An individual who has astigmatism has an abnormal curve in the optical part of the eye. The abnormal curve is usually in the cornea, but sometimes the lens is involved. When light enters the eye, it produces a smeared image rather than an image in sharp focus.

What are the causes and risks of the condition?

Astigmatism usually occurs naturally. It is caused by an abnormal curvature or shape of the cornea or lens. Injury to the cornea, or any other factor that could change the shape of the cornea or lens, can also cause astigmatism.


Symptoms & Signs

What are the signs and symptoms of the condition?

Symptoms of astigmatism include blurred vision, objects that appear fatter or taller than they really are, and a smeared focus.


Diagnosis & Tests

How is the condition diagnosed?

Diagnosis is usually made by an eye-care professional during an eye exam. It can also be diagnosed using instruments that measure the curve of the cornea. Other instruments can make a map of the cornea.


Prevention & Expectations

What can be done to prevent the condition?

There is no way to prevent astigmatism. The eye develops this way in some people.

What are the long-term effects of the condition?

If astigmatism is not corrected early in life, it is possible to develop lazy eye, also called refractive amblyopia.


Treatment & Monitoring

What are the treatments for the condition?

Glasses or contact lenses can be prescribed to control the light coming into the eye. The glasses or contact lenses direct the light to a point focus on the retina, so the image doesn't appear smeared.

Recently, corneal surgery procedures have become recognized as a possible treatment for astigmatism. Cuts in the cornea or the use of lasers or other surgical techniques on the cornea have been shown to reduce or get rid of astigmatism.

What are the side effects of the treatments?

Contact lenses may cause injury to the cornea. Surgery may cause bleeding, infection, or allergic reaction to anesthesia.

What happens after treatment for the condition?

Once astigmatism is corrected, the person will have normal vision.

How is the condition monitored?

Astigmatism is monitored during routine eye examinations. Any new or worsening symptoms should be reported to the healthcare provider.


Attribution

Author:William Stevens, MD
Date Written:
Editor:Ballenberg, Sally, BS
Edit Date:09/13/01
Reviewer:Sal Sandoval, MD
Date Reviewed:09/17/01