Astigmatism (uh-STIG-muh-tiz-um) is a common, mild and generally easily treatable imperfection in the curvature of your eye. The condition can cause blurred vision.

Astigmatism occurs when the front surface of your eye (cornea) or the lens, inside your eye, has a slightly different surface curvature in one direction from the other. Instead of being even and smooth in all directions, the surface may have some areas that are flatter or steeper.

Astigmatism blurs your vision at all distances. Astigmatism is often present at birth and may occur in combination with nearsightedness or farsightedness. Often it's not pronounced enough to require corrective action. When it is, your treatment options include corrective lenses and surgery.

Symptoms Causes

Signs and symptoms of astigmatism may include:

  • Blurred or distorted vision
  • Eyestrain
  • Headaches

When to see a doctor

If your quality of vision detracts from your enjoyment of activities or interferes with your ability to perform everyday tasks, see an eye doctor. An eye doctor can determine whether you have astigmatism and, if so, to what degree. He or she can then advise you of your options to correct your vision.

If you're a healthy adult older than 40, have your eyes examined about every two to four years until age 55.

After age 55, have them checked every one to three years for signs of eye disease or problems and after age 65, every one to two years.

If you have eye problems, such as astigmatism, you may need to have your eyes checked more frequently. If you're at risk of certain eye diseases, such as glaucoma, or you have diabetes, check with your doctor to see how often you need to have your eyes examined.

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