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What Does Refractive Surgery Mean?

Posted by fasttrack on September 25, 2016

what_does_refractive_surgery_mean.jpgRefractive surgery is eye surgery that is performed to eliminate or reduce dependency on contact lenses or glasses, although some people still need prescription eye glasses or contacts after the procedure. It is used to improve the refractive state of the eye which improves natural vision.

Refractive surgery can include a variety of methods of surgery that remodel or change the cornea.  Excimer lasers are used most commonly to reshape the curvature of the cornea.  Refractive surgery is a way to correct nearsightedness, farsightedness, and some types of astigmatism.  The most widely performed type of refractive surgery is LASIK.

Light rays enter the eye through the clear cornea, pupil and lens. These light rays are focused directly onto the retina, the light-sensitive tissue lining the back of the eye. The retina converts light rays into impulses, sent through the optic nerve to your brain where they are recognized as images. About 70% of the eye’s focusing power comes from the cornea and 30% from the lens.

Many forms of refractive surgery improve vision by permanently changing the shape of the cornea, the clear front window of the eye. In Greenville, Dr. Donelson uses LASIK to improve the following conditions:

Refractive Surgery for Myopia:

In an eye with myopia (nearsightedness), the corneal focusing power is too strong for the eye’s overall length. Instead of focusing on the retina, images fall in front of it, and vision is blurry. When treating myopia, certain refractive surgery techniques reduce the curvature of the cornea to lessen the eye’s focusing power. Images that are focused in front of the retina, due to an elongated eye or steep corneal curve, are pushed closer to or directly onto the retina following surgery.

Refractive Surgery for Hyperopia:

In an eye with hyperopia (farsightedness), the corneal focusing power is too weak for the eye’s overall length. Instead of focusing on the retina, images focus beyond the retina, and vision is blurry. When treating hyperopia, certain refractive surgery techniques make the cornea steeper to increase the eye’s focusing power. Images that are focused beyond the retina, due to a short eye or flat cornea, are pulled closer to or directly onto the retina following surgery.

Refractive Surgery for Astigmatism:

Astigmatism occurs when the cornea is more curved in one direction than the other, like the shape of a football. If astigmatism is significant, light passing through the cornea is scattered. Images reaching the retina are distorted and vision is blurred. When treating astigmatism, refractive surgery techniques selectively reshape portions of the cornea to make it symmetrical and smooth, like the shape of a basketball, so that images focus clearly on the retina.

If you are interested in reducing your dependence on contact lenses or eye glasses and would like to investigate refractive surgery as an option, please contact Donelson Eye Associates in Greenville at 864-987-0034 or donelsoneye.com to schedule a consultation.