Astigmatism is an irregular curve in the eye. Normal eyes are spherical. An eye with astigmatism is more oval in shape. This makes it difficult for light to focus on it well, which causes vision to be blurry. Each eye can have a different astigmatism, and it is possible to have one eye with astigmatism and one without.
Astigmatism can be corrected with glasses or contact lenses. Due to recent advances in technology, you may be able to wear soft contact lenses if you have astigmatism. These special lenses are called torric lenses. However, rigid gas permeable lenses may offer the best option to more accurately correct your vision because the rigid lenses help to smooth out the astigmatism.
Astigmatism can also be corrected with surgery. Laser-assisted in situ keratomileusis, or LASIK, surgery can be done on eyes with less than six diopters of astigmatism. A diopter is the measurement of the severity of the astigmatism. Any measurement of four diopters or more is considered extreme astigmatism. If it is over six, it is not safe to correct it with surgery because too many changes need to be made to the eye. If surgery is possible, it involves using a laser to sculpt the cornea into the proper shape. Astigmatism can be corrected when surgery is done to correct other eyes problems as well. People who undergo cataract surgery may opt to have their eye lenses replaced with artificial lenses. This will correct their vision and do away with the astigmatism.
The symptoms of astigmatism include blurred vision, eyestrain, and headaches. Children often do not realize that they are not seeing correctly and will not complain about their vision. Parents should watch for complaints of headaches, squinting, tired eyes, and problems in school. When children cannot see at school, they may act out or they may have difficulty learning. An eye doctor can easily diagnose astigmatism and correct it. Regular eye exams are an easy way to diagnose and track all eye problems, including other eye diseases.
During an eye exam, the doctor will do a visual acuity test as well as a keratometry test. The keratometry test uses light to reflect back the curvature of the cornea. This lets the doctor know if the surface of the eye has the wrong curvature. The doctor may also perform a refraction test. This test uses lenses to see how the patient’s eyes reflect light back to the doctor. This allows the doctor to learn which type of lenses will correct the patient’s vision.
Astigmatism is very common. It can be so slight that it does not need to be corrected, but it is not uncommon for people with nearsightedness or farsightedness to additionally have astigmatism. Astigmatism may change while the eye continues to grow, but this usually stops by adulthood. For this reason, surgery to correct astigmatism is discouraged until the patient is at least eighteen years old.
The astigmatism correction is in the second and third parts of an eyeglass prescription. The first part tells how nearsighted or farsighted the patient is. The second part shows the measure of the cornea in diopters. The third part tells how the lenses need to be made to correct the problem.