Laser Eye Surgery & Astigmatism
What is Astigmatism?
Astigmatism is a common vision problem – so common that as many as one-third of all people might suffer from it to varying degrees. In fact, some people with small amounts of astigmatism might not experience a noticeable effect on the clarity of their vision.
Astigmatism is a vision problem caused when the clear front cover of the eye (the cornea) is shaped irregularly. Because of this, a person isn’t able to focus light clearly as it enters the eye. The cornea is supposed to be round in shape, like the top of a globe; people with astigmatism have corneas that are egg shaped – imagine half a football instead of a baseball. When they look at something, light entering the eye bends unequally, resulting in blurriness or vision distortion.
Laser eye surgery for astigmatism correction can be an option for someone who suffers from mild or moderate astigmatism. Astigmatism correction offers a number of benefits – not only is vision impacted, but people with astigmatism frequently suffer from eyestrain and headaches as well. These, too, can often be relieved once the astigmatism has been treated.
LASIK and Astigmatism
Laser eye surgery for astigmatism alters the curvature of the cornea. By re-shaping the cornea into a more spherical shape with LASIK surgery, astigmatism’s refractive error is resolved when the front surface of the eye becomes more symmetrical. This astigmatism correction then allows light to properly come through the cornea to the back of the eye and focus on images more clearly.
Astigmatism may occur in one or both eyes; only the affected eye needs to be treated with LASIK surgery. Due to the irregular eye shape in people with astigmatism, light hits the eye at multiple points (it should be just a single point). This sends mixed signals to the brain, resulting in blurry vision. Astigmatism correction is achieved when laser eye surgery reshapes the inner layer of the cornea, which then allows light entering the eye to come to a single focus on the inner layer of the eye (retina).