What Is Astigmatism? - SightMD Skip to main content

February 21, 2022

By: Jeffrey Martin, MD

What Is Astigmatism?

Astigmatism vs. normal vision

Astigmatism is a common vision problem caused by an error in the shape of the cornea. With astigmatism, the lens of the eye or the cornea, which is the front surface of the eye, has an irregular curve. This can change the way light passes, or refracts, to your retina, causing blurry, fuzzy, or distorted vision.

Farsightedness and nearsightedness are two other types of problems with the way light passes to your retina. Farsightedness is called hyperopia. Nearsightedness is called myopia.

What are the different types of astigmatism?

The two main types of astigmatism are corneal and lenticular. A corneal astigmatism happens when there’s a defect or distortion in the cornea. A lenticular astigmatism happens when there’s a distortion in the lens.

Astigmatisms are sometimes also described as regular or irregular. A regular astigmatism occurs when the eye isn’t completely curved. So instead of being round like a basketball, it might take the shape of a football. This often leads to blurry, distorted vision.

An irregular astigmatism, which is less common, also occurs when the eye isn’t completely round. But unlike a regular astigmatism, where the eye is evenly misshaped, an irregular astigmatism has an uneven curvature. This defect also causes distorted vision and blurriness.

Who’s at risk for astigmatism?

Astigmatism can occur in children and adults. Your risk of developing astigmatism may be higher if you have any of the following:

  • a family history of astigmatism or other eye disorders, such as keratoconus (degeneration of the cornea)
  • scarring or thinning of your cornea
  • excessive nearsightedness, which creates blurry vision at a distance
  • excessive farsightedness, which creates blurry close-up vision
  • a history of certain types of eye surgery, such as cataract surgery (surgical removal of a clouded lens)

What are the complications associated with astigmatism?

If left untreated, astigmatism can cause complications. For example, a lazy eye (amblyopia) can occur when a person has astigmatism in only one eye, or the astigmatism in one eye is worse than the other, and the condition isn’t corrected. Additionally, astigmatism can sometimes cause eye strain and headaches.

Astigmatism can also be corrected during cataract surgery, however, any surgery to treat astigmatism also has risks. Side effects of surgery are often temporary and improve within a few weeks. These include dry eyes, sensitivity to light, and night vision problems.

But other (and more permanent) complications can occur, too, such as vision loss or vision reverting to pre-surgery state.

Contact SightMD today to schedule an appointment with one of our doctors to discuss your vision health at one of our convenient locations!