What Is Astigmatism?
Astigmatism is a common vision condition 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. This causes 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.
It’s a big word, but it simply means your eye isn’t completely round. Almost all of us have it to some degree.
A normal eyeball is shaped like a perfectly round ball. Light comes into it and bends evenly, which gives you a clear view. But if your eye is shaped more like a football or the back of a spoon, light gets bent more in one direction than another. That means only part of an object is in focus. Objects at a distance may look blurry and wavy.It’s fairly easy for an eye doctor to fix with glasses, contacts, or surgery.
What Causes Astigmatism?
It’s not known what causes astigmatism, but genetics is a big factor. It’s often present at birth, but it may develop later in life. It may also occur as a result of an injury to the eye or after eye surgery. Astigmatism often occurs with nearsightedness or farsightedness.
Who Is 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 a degeneration of the cornea called keratoconus
- 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 Symptoms of Astigmatism?
The symptoms of astigmatism may differ in each person. Some people don’t have any symptoms at all. The symptoms of astigmatism include:
- blurry, distorted, or fuzzy vision at all distances (close-up and far away)
- difficulty seeing at night
- eye irritation