The first type of laser surgery for the eyes is called PRK which stands for photo refractive keratectomy. More popular today is what is known as LASIK and LASEK and variations thereof. Since 1995 the FDA has approved of a limited number of laser surgeries to correct refractive problems.
PRK was practiced in the early 1980’s in other countries before being approved in this Country. Some surgeons still prefer to use PRK in patients with thin corneas or large pupils. An ultraviolet light beam is used to remove very tiny pieces of tissue from the cornea to reshape it. People who are both nearsighted and farsighted can be helped by this surgery. To correct nearsightedness the cornea is flattened whereas the opposite happens for farsightedness. An irregular-shaped cornea is smoothed out to correct Astigmatism.
Usually this surgery can be performed as an outpatient using local anesthetic eye drops.  Measurement of the eye is taken to find out the degree of the problem and a map of the surface is made. The needed corrections are calculated and entered into the laser computer. The surgery itself takes only a few minutes. Most patients can resume normal activity in just a few days.
LASIK is used to correct the same type of visual problems. A thin flap in the cornea is made using a microkeratome blade or a femtosecond laser. It is then folded back and tissue is removed from underneath the cornea by means of an excimer laser. It is then put back in place covering over the area where the tissue was removed.
The advantages of LASIK over PRK are that it can correct severe refractive errors and that in general the recovery time is less. Usually right after surgery patients can drive and better vision is experienced is one week.LASIK is normally an outpatient surgical procedure. As you look at a targeted light for a short duration the laser sends pulses to reshape your cornea. All this can be done in less than five minutes.
A competent eye surgeon be able to tell you if LASIK surgery is recommended for you. He can look at factors like the structure of your eyes, your age, and general health. If he feels you do not qualify for LASIK, he may suggest either PRK, LASEK, or maybe other methods to help you with your eyesight.
LASEK is a procedure that’s done to preserve the very thin epithelial layer by lifting it from the surface of the eye before reshaping the eye by laser energy. Then this layer is placed back on the eye. A very thin flap is made with a tool called a trephine, whereas with LASIK surgery a thicker flap is made with a microkeratome tool.
So when it is found that a patient’s cornea is either too thin or too steep for LASIK surgery LASEK may be recommended. The healing process usually takes longer for LASEK patients and some reports show that there are more complaints of discomfort after surgery.
Before deciding to have any surgery whether it is  laser surgery for the eyes or eyelid surgery you should research all options thoroughly. Studies are being conducted to ascertain what the results to vision will be over the long term.