Lasik Eye Surgery

For centuries those with a common vision problem have required glasses to correct it. Then in 1917 Albert Einstein came up with the theory for laser light, and in 1954 Charles Townes and Arthur Schawlow were the first to apply this theory in making the maser (precursor to the laser). Supposedly, when laser was invented, a scientist commented, “Well, we have a laser, but what is it good for?” Today lasers touch the lives of every American daily through CD and DVD players, photocopiers, and laser printers, to name just a few. Specifically here, the use of lasers in eye surgery means that, for many, glasses are no longer required. The surgical process is called Lasik eye surgery.

What is Lasik Eye Surgery?

Lasik is an acronym for Laser-Assisted in SItu Keratomileusis. For those interested, “in situ” means “in a localized area”, while keratomileusis refers to working through the cornea.

How the Eye Works

Perhaps a quick lesson on how the eyeball works would be helpful here. Light enters the eyeball by passing through the cornea, the outer disk, filled with a liquid called the aqueous humor. The light then passes through the pupil and is refracted by the lens. This means the light is bent out or in so that it focuses on the retina, the back of the eyeball. At the retina, light is converted into electrical impulses that are then sent via the optic nerve to the brain.

If the eyeball is too long, light focuses in front of the retina, causing blurry vision of distant objects. This is called myopia or nearsightedness. Until recently, the only way to correct this is by placing a concave lens in front of the eye thus bending the light out so that it focuses correctly on the retina. If the eyeball is too short, the light has not focused by the time it reaches the retina. This is called hyperopia or farsightedness. A convex lens helps to bend the light in so that it will focus sooner. Astigmatism is caused when either the cornea or lens shape is distorted. This causes multiple images on the retina giving blurry vision at all distances.

How Lasik Removes the Need for Glasses

If through Lasik eye surgery the cornea can be reshaped to correct the problem of eyeball shape, any of these vision problems can be corrected without the need of glasses. What is involved in Lasik surgery? “An instrument called a microkeratome is used in LASIK eye surgery to create a thin, circular flap in the cornea. The surgeon folds the hinged flap back out of the way, then removes some corneal tissue underneath using an Excimer laser. The Excimer laser uses a cool ultraviolet light beam to precisely remove very tiny bits of tissue from the cornea to reshape it.” With nearsighted people, the goal is to flatten the cornea; with farsighted people, a steeper cornea is the goal. The Excimer laser is also used to correct astigmatism by smoothing an irregular cornea into a more normal shape.

Lasik eye surgery is very popular. Since it was approved in the United States in 1995, an average of four million surgeries are performed annually. Several reasons explain its popularity. First, it does not need hospitalization but can be done in an ophthalmologist’s office. Second, it is relatively painless for the patient. Third, most experience almost instant vision correction. Another similar procedure is called photorefractive keratectomy (PRK) but Lasik generally provides quicker patient recovery.