You may have heard the word “astigmatism,” and maybe you’ve even been diagnosed with it — but do you really know what it is? 

Astigmatism is an incredibly common condition, affecting as much as 30 percent of the U.S. population. But many of our patients don’t know what it means about their vision.

That’s why we’re breaking down the basics about the condition in today’s blog.

Defining Astigmatism
First things first — astigmatism occurs when the cornea or lens in your eye is misshapen. In a “normal” eye, the cornea and lens curve equally in both directions and are smooth.

In a person who has astigmatism, on the other hand, either the cornea or the lens is curved abnormally, which can lead to difficulty seeing and blurred vision. That’s because the curvature keeps light from focusing properly on the retina, which is the part of your eye that’s sensitive to light. This is called a “refractive error.”

If the cornea is the part of your eye that’s abnormally curved, you’ll be diagnosed with corneal astigmatism. If the lens is curved, you have lenticular astigmatism.

Because the condition leads to blurry vision and difficulty seeing, it can also contribute to symptoms like headaches and eyestrain, particularly over time.

How Astigmatism Is Diagnosed
During a comprehensive eye exam, your doctor will check you for astigmatism. This is done through what’s known as a “visual acuity test,” which you probably know better as the chart that you read letters from. 

This test helps your doctor determine how clear your vision is at different distances — and can reveal when your vision is blurred and unclear, as is the case with astigmatism.

If your doctor believes you may have astigmatism, he or she will then use several tools to help determine the appropriate way to treat your condition. This will include tests designed to help measure the curvature of your cornea, as well as the use of an instrument that can show how your eyes focus light. 

Astigmatism often accompanies other vision disorders, such as nearsightedness or farsightedness, so your exam will likely also include tests to diagnose and monitor those conditions.

How Astigmatism Is Treated
Because untreated astigmatism negatively impacts your vision, your doctor will recommend a treatment plan once you’re diagnosed.

There are several options available to treat astigmatism:

• Glasses. Eyeglasses for those who have astigmatism will contain a specialized prescription with additional strength in certain parts of the lens. This compensates for any deficits caused by the astigmatism.
• Contact lenses. Some patients are more comfortable using contact lenses rather than glasses. Normal contact lenses may be ineffective when treating astigmatism, but there are options such as toric contact lenses and rigid gas-permeable contact lenses that may help improve vision.
• Laser vision correction. Procedures such as PRK can also be used in certain cases to reshape the cornea and correct vision.

Treatment for astigmatism isn’t one size fits all. The best treatment for you will depend on your specific needs and your overall health and lifestyle. You and your doctor can determine what will work best given your circumstances.

Believe you may have astigmatism? A comprehensive eye exam can help diagnose the underlying cause of your vision difficulties. Contact us to set up an appointment!