Correcting Your Vision With LASIK

LASIK can correct most vision problems including astigmatism, nearsightedness and farsightedness.

There are three main parts to the eye that cause vision problems: the cornea, the lens and the retina. The cornea is in the front of your eye. When you look at an object, the cornea first bends, or refracts, light. This light should be focused directly through your lens and on to your retina at the back of your eye. Any abnormality in the shape of your cornea will cause the light to bend and focus differently and cause images to blur. Depending on your specific refractive error, you can sometimes see up close or far away, but not both. LASIK corrects 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 help with this focusing power.

LASIK solves 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 through very small dots on the edge of the cornea. As the tissue around these dots shrink, the center of the cornea starts to bulge outward.

Astigmatism

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 effectively corrects astigmatism by rounding the edges of the cornea.