Refractive Surgery Basics

Refractive Eye Surgery - The goal of refractive surgery is to help reduce or even eliminate your need for glasses or contact lenses. Various surgical procedures are available to help correct nearsightedness (myopia), farsightedness (hyperopia) and astigmatism.


Myopic patients can see well up close without glasses but need glasses to see well at a distance. Myopia arises when the eye’s focusing power is too great. Due to this excess focusing power, light rays come to focus in front of the retina. Hyperopic patients see better at a distance than up close, but may not see as well as desired at either distance. Hyperopia arises when the eye’s focusing power is deficient. Due to this deficient focusing power, light rays theoretically come into focus behind the eye. Astigmatism is a refractive error characterized by light rays focusing at two different locations inside the eye. The type of astigmatism is determined by the location of those two focal points.

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Refractive surgery improves your vision by changing the focusing power of your eye. This change is accomplished by altering either of the eye’s two focusing structures, the cornea and the lens, by various surgical techniques.

The most common corneal refractive surgery procedure is LASIK (laser-assisted in situ keratomileusis). In LASIK, an excimer laser is used to reshape your cornea. Traditionally, a thin flap is cut on the surface of your cornea with a special instrument called a microkeratome; the flap is folded out of the way. Laser energy is then used to sculpt your exposed cornea to correct your nearsightedness. The flap is then put back into its normal position, covering the treated area. Recent technology, such as the femtolaser system (used to make a more precise flap) and wavefront analysis, has led to even greater success in LASIK surgery. Most patients can see improvement in vision immediately after surgery.

LASIK is also used to correct hyperopia. However, the corneal reshaping process in hyperopic LASIK is opposite from the process in myopic LASIK. In hyperopic LASIK, a ring of tissue is removed from the cornea’s outer edge. As a result, the center of the cornea bulges out, thus increasing the eye’s refractive power. In myopic LASIK, the central cornea is flattened.

A slightly different procedure, called LASEK (laser epithelial keratomileusis), uses a thinner flap, and is typically performed in people whose cornea is too thin or too flat for LASIK. A third type of corneal refractive surgery is called PRK (photorefractive keratectomy), which differs from LASIK and LASEK in that no flap is made, and the laser directly sculpts the front surface of your cornea.

There are two modern-day refractive surgery procedures that do not involve the cornea. One involves the implantation of a special lens that sits inside the eye just in front of the eye’s natural lens. The strength of the implant is specifically selected to work with your cornea and lens to correct your refractive error. The second procedure is called RLE (refractive lens exchange). Refractive lens exchange involves removing your clear natural lens and replacing it with a lens implant that works with your cornea to correct your refractive error. Implants used for RLE are the same as those used for cataract surgery.

All refractice surgery procedures have different risks and benefits, and all are designed for different groups of people based on the type and severity of their refractive errors. If you are considering having refractive surgery in Kentucky, talk with your doctor about which procedure is best for you.

This Kentucky refractive surgery resource is intended to highlight relevant considerations in a summary manner and should not be construed as individual medical advice. If you have specific questions regarding refractive surgery in Kentucky please contact us directly.


Kentucky Eye Institute is comprised of both ophthalmologists and primary care optometrists. We invite you to read about our doctors on this website and explore the vast experience we possess as one of the region’s premier eye care providers. If you have any questions please feel free to contact us.


Are you a candidate for LASIK eye surgery in Lexington or the surrounding Areas? Take our test and hear from our LASIK eye surgery consultants. Get started today on your path to visual freedom!


Would you like to have LASIK refractive surgery but are concerned about finances? Kentucky Eye Institute has multiple financing options available to make LASIK affordable for almost everyone. There is a page on this website dedicated to discussing LASIK financing options. You can even fill out an online application to see if you qualify. Kentucky Eye Institute offers 0% financing, with approved credit, with low fixed monthly payments, no down payment and no pre-payment penalties.


Learn all about cataract surgery. We have the latest Premium Lens Implant Technology available for patients wishing to see better after cataract surgery. Patients now have the option to see better at all distances including near, far and intermediate. If you are seeking Cataract Surgery in Kentucky please feel free to contact us.


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