lasik
LASIK is an outpatient surgical procedure approved by the Food and Drug Administration (FDA). A surgeon uses the Excimer laser developed by IBM in the early 1990s to correct refractive errors - such as nearsightedness or farsightedness with astigmatism. Because this laser uses a cool beam, heat or scarring does not occur.
LASIK is now the most popular surgical procedure in the United States. Recently, the FDA approved a new and improved version of LASIK called wavefront technology. Wavefront diagnostic testing is 25 times more precise than previous methods, and incorporates data about the entire visual system which makes the procedure more customized.
Since Federal Drug Administration (FDA) approval in 1996, almost five million Americans have enjoyed the benefits of clear vision with LASIK surgery - and ended their dependence on eyeglasses and contacts. Almost half of all Americans have some type of refractive error - and a third of them (50 million) are potential LASIK candidates.
When an individual has clear vision without glasses or contacts, light rays enter the eye through the front portion of the eye known as the cornea where they ultimately are focused on the retina. The retina converts these light images into electrical pulses where they are passed through the optic nerve to the brain.
When the cornea is not shaped properly, the light does not focus properly on the retina. This condition is known as a refractive error. The three types of common refractive errors are nearsightedness (myopia), farsightedness (hyperopia) and astigmatism.
Nearsightedness occurs when the cornea of the eye is too steep in curvature, causing light rays to focus in front of the retina. With nearsightedness, near images are in focus, while far objects are blurred.
Farsightedness occurs when the cornea of the eye is too flat in curvature, causing light rays to focus behind the retina. With farsightedness, far images are in focus, while near objects may be blurred.
Astigmatism occurs when the surface of the cornea has an irregular shape, causing light rays to focus on multiple points within the eye causing vision problems for both near and far objects. Astigmatism can occur with nearsightedness or farsightedness.
LASIK does NOT correct presbyopia (reading glasses) because this condition is caused by the hardening of the material in the lens located inside the eye. Much like a camera shutter, eye muscles squeeze on the lens to flatten it for fine reading. When this material hardens, the lens cannot flatten sufficiently to read small print. LASIK surgeons can compensate for presbyopia by correcting one eye for near and the other for far vision. Consult your doctor about the special conditions of this surgery, called monovision. The doctor can help simulate monovision with special contacts to see if monovision LASIK is right for you.