Of the three main types of refractive errors, patients generally have a good understanding of two of them:
- Nearsightedness describes when a patient can see clearly up close but objects in the distance become blurry.
- Farsightedness describes when a patient can see objects far away clearly but objects up close are blurry.
However, when patients are diagnosed with astigmatism, they often ask for a definition. Astigmatism may be less understood, but it is no less common. In fact, about one in three Americans have measurable astigmatism. Here, the eye doctors at Clarity Eye Group provide more information about this refractive error.
What Is Astigmatism?
Patients who have astigmatism have difficulty seeing both near and distant objects. This occurs due to irregularly shaped corneas or lenses. (Usually, astigmatism affects both eyes, though in rare cases it may affect just one.) Whereas a properly shaped eye is round and spherical, an eye with astigmatism has uneven curvature, more like an egg or a football.
On an eyeball with an evenly rounded cornea and lens, the incoming rays of light move correctly to the retina to allow for normal sight. However, if an eyeball has an irregular shape, the light rays bend incorrectly, causing them to miss the retina and therefore not communicate properly with the brain.
It is possible to have astigmatism as well as nearsightedness or farsightedness.
Causes of Astigmatism
Doctors do not have a definitive explanation for why some corneas are shaped differently from others. However, most clues point to this being determined by genetics since it is common for parents to have children with similar types of astigmatism.
While most patients with astigmatism have had it since birth, this condition can sometimes develop later in life due to other factors like eye disease, a traumatic injury to the eye or an eye surgery. Patients who notice a change in their vision should schedule an eye test to update their existing prescription.
Patients who ignore astigmatism have a difficult time seeing objects at all distances. They may also develop eyestrain and headaches from squinting to try to make out objects anyway.
Fortunately, astigmatism is not difficult to correct. Most patients use prescription lenses (either eyeglasses or contact lenses) to overcome astigmatism. Since astigmatism does not go away, this is a lifelong necessity.
Another great option is to have laser eye surgery. LASIK and PRK are two popular refractive procedures that correct the shape of the cornea. Once the eyeball is reshaped, light can pass through normally, which enables clearer vision at all distances. Many patients prefer to undergo one of these easy surgeries over having to wear prescription lenses constantly.
Visit Clarity Eye Group
Patients in Huntington Beach and Newport Beach who are due for a comprehensive eye exam or who would like to permanently correct their astigmatism with a refractive surgery like LASIK should schedule an appointment with one of our skilled doctors. Please call (714) 842-0651 or make an appointment directly online.