Astigmatism is a common cause of blurry vision. It’s a refractive error, like nearsightedness or farsightedness, but it causes distorted vision at all distances. It occurs when the cornea is more oval than spherical in shape. Some doctors describe an eye with astigmatism as being shaped more like an American football than a soccer ball.
When the cornea is misshapen, it results in two points for light to focus on instead of one. This causes the common symptoms of astigmatism to appear, including blurry vision, distorted vision, headaches, squinting, eye strain and fatigue. Keep reading to get answers for 9 of the most common questions about this condition that affects 1 in 3 Americans.
Sometimes the condition is apparent at birth, but it usually occurs a little later in life along with myopia (nearsightedness) or hyperopia (farsightedness. Under the age of 15, about 14.3% of people have astigmatism, while 67.2% of people aged 65 and over have it. Interestingly, babies who are born with the condition often outgrow it by age 5.
Although doctors aren’t sure why some people have the cornea shape that causes astigmatism, they know that the condition can be inherited from your parents. Some people are born with the condition, while others develop it after a disease, injury or surgical procedure involving the eyes.
Contrary to popular belief, sitting too close to the TV or other screens doesn’t cause astigmatism. It’s also not caused from reading in low light.
Yes, without treatment—and especially in children—astigmatism can lead to amblyopia, or lazy eye. This happens when one eye has stronger astigmatism, myopia or hyperopia and the brain starts to “tune out” the visual signals coming from that eye. Vision therapy can usually correct the condition.
If contact lenses aren’t fitted properly or worn for too long, they can deprive the corneas from receiving the oxygen they need. In some cases, this could develop into contact lens-induced astigmatism.
Fortunately, this type of astigmatism can usually be reversed by switching to eyeglasses for a while and wearing a different type of contact lenses after the cornea heals.
It’s common for people to need a time of adjustment to get used to any new corrective lens prescription. This is especially true if it’s been a while since your last exam and your prescription had significant changes. Usually, dizziness and other discomforts vanish after a few days. If yours lasts a week or more, schedule another visit with us to verify that your prescription is correct.
Ironically, LASIK surgery can do both. Because the procedure changes the shape of the cornea, it’s often a good way to treat astigmatism in people over the age of 20. (It’s not recommended for children or teenagers as their eyes are still growing.)
But people who undergo LASIK or cataract surgery may find that the procedure causes post-surgical astigmatism that wasn’t there before.
Mild and moderate cases can be managed with prescription eyeglasses, toric contact lenses, or scleral contact lenses. Toric and scleral contacts are special types of contact lenses designed to account for the distorted shape of an eye with astigmatism.
A comprehensive eye exam will tell your ophthalmologist if you have the condition. During the exam, they’ll measure the curvature of your corneas and also test how your eyes refract light onto your retinas. If you suspect you have astigmatism, call or text us at (423) 855-8522 today to schedule an appointment for a detailed eye exam.