BEFORE: You'll need a complete eye examination by your refractive surgeon. A preliminary eye exam may be performed by a referring doctor (Eye MD or optometrist). Take your eye prescription records with you to the exams.
Your doctor should:
Dilate your pupils to fine-tune your prescription.
Examine your eyes to make sure they're healthy. This includes a glaucoma test and a retina exam.
Take the following measurements:
           • The curvature of your cornea and your pupils. You may be rejected if your pupils are too large.            • The topography of your eyes to make sure you don't have an irregular astigmatism or a
              cone-shaped cornea — a condition called Keratoconus.
           • The pachymetry — or thickness — of your cornea. You need to have enough tissue left after               your corneas have been cut and reshaped.
Ask you to sign an informed consent form after a thorough discussion of the risks, benefits,
    alternative options and possible complications. Review the form carefully. Don't sign until you     understand everything in the form.
If your doctor doesn't think LASIK is right for you, you might consider getting a second opinion;     however, if the opinion is the same, believe it.

If you qualify for surgery, your doctor may tell you to stop wearing your contact lenses for a while before the surgery is scheduled because contacts can temporarily change the shape of the cornea. Your cornea should be in its natural shape the day of surgery. Your doctor also may tell you to stop wearing makeup, lotions or perfume for a few days before surgery. These products can interfere with the laser treatment or increase the risk of infection after surgery.

DURING: LASIK is an outpatient surgical procedure. The only anesthetic is an eye drop that numbs the surface of the eye. The surgery takes 10 to 15 minutes for each eye. Sometimes, both eyes are done during the same procedure; but sometimes, surgeons wait to see the result of the first eye before doing the second eye.

The Surgical Procedure: A special device cuts a hinged flap of thin corneal tissue off the outer layer of the eyeball (cornea) and the flap is lifted out of the way. The laser reshapes the underlying corneal tissue, and the surgeon replaces the flap, which quickly adheres to the eyeball. There are no stitches. A shield - either clear plastic or perforated metal — is placed over the eye to protect the flap.

AFTER: Healing is relatively fast, but you may want to take off a few days after the surgery. Be aware that:
You may experience a mild burning or sensation for a few hours after surgery. Do not rub your eye(s).     Your doctor can prescribe a painkiller, if necessary, to ease the discomfort.
Your vision probably will be blurry the day of surgery, but it will improve considerably by the next day         when you return for a follow-up exam.
If you experience aggravating or unusual side effects, report them to your doctor immediately.
Do not drive until your vision has improved enough to safely do so.
Avoid swimming, hot tubs and whirlpools for two weeks after surgery.

Click here to read more about What to Expect - Source: Food and Drug Administration