Astigmatism is a common type of refractive error. It means that some part of your eye (either the cornea or lens) is more curved than it should be. This altered eye shape makes your vision blurry. Most cases of astigmatism can be treated with corrective lenses like eyeglasses or contact lenses.
Usually, eyes are round, like a baseball. If you have astigmatism, your eye is shaped like a football or the back of a spoon. This makes light that enters your eyes bend unevenly and affects your vision at all distances.
Visit an eye care specialist as soon as you notice any changes in your eyes or feel like your vision isn’t as clear as it used to be.
The parts of your eyes work together like a relay team to pass light that enters your eye along a pathway to your brain. Light passes through your cornea — the clear part at the front of your eye. Your cornea focuses that light through your lens into a signal that hits your retina — the layer at the very back of your eyeball. Your retina converts that light into electrical signals that your optic nerve sends to your brain. Your brain then uses those signals to create the images you see.
If you have astigmatism, light that enters your eye is bent more than it should be. The light can’t properly focus on your retina. This means only parts of an object you’re looking at are in focus. That uneven focus makes objects look blurry or wavy. Astigmatism can affect your vision at any distance — both up close and farther away.
You might experience eye strain — like your eyes are constantly working too hard to see.
Astigmatism is usually caused by your cornea having an irregular shape. Eye care specialists call this corneal astigmatism.
You can also have lenticular astigmatism, where the lens in your eye has an irregular shape. Lenticular astigmatism is often caused by cataracts.
Some people have both corneal and lenticular astigmatism.
Anyone can experience astigmatism. You can develop it at any point in your life. Some people are born with astigmatism. Others don’t develop it until they’re adults. It can get better or worse over time.
Astigmatism is very common. 1 in 3 people has astigmatism.
Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy
Blurred vision is the most common astigmatism symptom. It also makes it hard to see details on objects, like the words printed on a menu in front of you, or letters on a road sign in the distance.
Other astigmatism symptoms include:
Some young children don’t know there’s anything wrong with their vision, even if they’re experiencing symptoms. Visit an eye care specialist if you notice your child squinting, rubbing their eyes or having frequent headaches.
Astigmatism is usually hereditary, which means it’s a condition biological parents pass down to their children. It can also be caused by your eyelids putting too much pressure on your cornea.
Astigmatism usually isn’t caused by health conditions. Some conditions and issues that can cause astigmatism include:
An eye care specialist will diagnose astigmatism with an eye exam. They’ll look at your eyes (including inside them).
Your eye care specialist might use a few tests to diagnose astigmatism, including:
If the astigmatism is very mild (and doesn’t affect your vision), you might not need glasses or contacts. Your eye care specialist will measure any changes in your eye during future eye exams. Astigmatism can change over time and get worse, so you might need glasses or contacts eventually, even if you don’t at first.
Wearing glasses or contacts will correct your vision, but they won’t change the shape of your eye. Vision correction surgery (including LASIK eye surgery and photorefractive keratectomy or PRK eye surgery) uses lasers to fix vision problems. A specially trained ophthalmologist will perform these procedures to change the shape of your cornea so light hits your retina correctly.
People who have cataracts and astigmatism can have both treated at the same time during cataract surgery.
These surgeries will reduce astigmatism and improve your vision. Talk to your eye care specialist if you’re interested in vision correction surgery.
You can’t prevent astigmatism. Most people who have astigmatism are born with it. Others develop it as their eyes grow and change throughout their lives.
If you have astigmatism or another type of refractive error, there’s a chance your children might as well.
Having your eyes and vision checked regularly can help an eye care specialist identify problems right away. How often you should get your eyes checked usually depends on your age.
You might need your eyes checked more often than this if you wear glasses, contacts or need another type of visual aid. People with diabetes also need their eyes checked more often than what’s listed here.
Ask an eye care specialist how often you need an eye exam.
If you have a small degree of astigmatism that doesn’t affect your vision, you might not need any treatment. If you have a significant astigmatism that makes it hard to see clearly, there are lots of ways your eye care specialist can treat it. Many people with astigmatism only need glasses or contact lenses.
Most people who have vision correction surgery have permanently improved vision. Some people need an enhancement procedure as they get older. This follow-up procedure will correct any changes in the astigmatism that happen after your eyes naturally change shape as you age.
Visit an eye care specialist as soon as you notice any changes in your eyes — especially if your vision is getting noticeably worse or blurry. Astigmatism symptoms are usually very noticeable at night, when it’s raining or when you look at lights.
A note from Cleveland Clinic
Astigmatism is a common condition that makes the shape of your eye more curved than it should be. The blurry vision astigmatism causes can be annoying and make it hard to participate in your daily routine. Fortunately, most people with astigmatism only need glasses or contacts to see clearly. Talk to your eye care specialist if you’re interested in vision correction surgery.
Young children probably won’t be able to understand or tell you that their vision is worse. Visit an eye care specialist if you notice your child squinting a lot or having frequent headaches.
Last reviewed by a Cleveland Clinic medical professional on 11/20/2022.
Learn more about our editorial process.