Astigmatism is a common vision disorder, often seen in conjunction with myopia (nearsightedness) or hyperopia (farsightedness). Astigmatism is due to an abnormal shape of the cornea, and causes vision to be blurry at all distances. Like these other vision issues, astigmatism can be corrected with LASIK eye surgery.
Causes of Astigmatism
Astigmatism occurs because the normally spherical-shaped cornea is oval instead. This causes light to be focused incorrectly on the retina, leading to blurred vision. Correcting an astigmatic involves either redirecting the light that passes through the eye so it is focused correctly or altering the shape of the cornea. Though most cases of astigmatism are congenital, it can also occur due to an injury to the eye or as a side effect of some eye diseases.
Until recently, only eyeglasses or hard contact lenses could provide effective correction for astigmatism. Today, however, toric contact lenses specially designed for astigmatism provide high-quality correction in either hard or soft lenses. In addition, LASIK eye surgery can be used to change the shape of the cornea for permanent improvement of astigmatism.
Types of Astigmatism
There are two types of astigmatism: corneal astigmatism and lenticular astigmatism. In corneal astigmatism, the cornea is shaped somewhat like a football, instead of like a sphere as it would be normally. Lenticular astigmatism occurs because of a similarly irregular shape of the lens of the eye. In either type of astigmatism, light is improperly focused on the retina, causing blurry vision.
Treatments for Astigmatism
Contact lenses have been used to treat myopia and hyperopia for many years. However, until recently, only hard contact lenses provided effective correction for astigmatism. Now special lenses called toric lenses are prescribed to treat this vision disorder. Most types of astigmatism can be corrected with soft toric lenses, while more severe astigmatism must still use hard lenses, glasses, or permanent correction via surgery.
The growth of laser treatment for vision problems has provided even more options for astigmatism correction. LASIK eye surgery, in which a laser is used to reshape the cornea, can provide permanent correction for astigmatism.
Although it is a relatively simple procedure that usually only takes 15 to 30 minutes, LASIK provides dramatic results. Unlike earlier laser surgery procedures like PRK that removed tissue from the surface of the cornea, LASIK makes use of a corneal flap—a thin layer of tissue partially detached from the cornea—to protect the area of the eye that has been surgically altered. This corneal flap allows for rapid healing. After LASIK surgery, you will experience improved vision almost immediately, and the corneal flap will heal to the eye almost completely in less than 24 hours.
For information on New York City area LASIK surgery, please visit the website of James Kelly, MD, of the Kelly Laser Center.