What Can LASIK Correct?

Greenville-South-Carolina-LASIK-Cataracts-Eye-Care-lasik-1.pngLASIK is one option to correct the three most common refractive errors (eyesight errors):

  1. Nearsightedness
  2. Farsightedness
  3. Astigmatism

To understand refractive errors and how LASIK can correct them, you first must understand how the eye works. The eye is made up of three main areas: the cornea, the lens and the retina.

The Cornea

The front part of the eye is the cornea. When you look at an object, the object reflects light that enters into your eye. It is the purpose of the cornea to bend, or refract, this light. In a perfect eye, the cornea refracts light directly through the lens and on to the retina, at the back of the eye. If the cornea is misshapen, then the light will bend and focus differently, causing images to blur. Depending on your specific refractive error, you can sometimes see up close or far away, but not both. LASIK may help to correct your vision by reshaping your cornea so light enters the eye as it was meant to.

Nearsightedness (Myopia)

For nearsighted individuals, the cornea is ‘steeper’ than it should be and light is focused in front of the retina. This means that the further away an object is, the harder it is for the eye to focus on it. Glasses and contacts can help with this focusing power.

LASIK treats nearsightedness by flattening the shape of the cornea, through very minuscule tissue removal (typically less than the thickness of a human hair) from the center of the cornea.

Farsightedness (Hyperopia)

People who can see distant objects more clearly than objects close up are said to be farsighted. A person with farsightedness has a flatter than normal cornea and light actually focuses behind the person’s retina. Because of this, close up objects are more blurry than far objects.

LASIK for farsightedness is conducted by steepening the edge of the cornea.


The cornea is meant to be shaped round, like a basketball. When someone has astigmatism, the cornea is steep but in an uneven way. This causes the edges of the cornea to appear more like a football – slightly pointed. This causes light to focus at several points in the back of the eye. Astigmatism is very common and can accompany any other form of refractive error, such as myopia or hyperopia.

LASIK may effectively treat astigmatism by rounding the edges of the cornea.

The only way to learn if LASIK is right for you is through a comprehensive Free LASIK Consultation. To schedule your Free LASIK Consultation at Donelson Eye Associates, give us a call at 800-273-3937.


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