How is LASIK surgery performed?
First, your LASIK surgeon will create a very thin, superficial flap in your cornea with a small surgical tool called a microkeratome or with a femtosecond laser.
LASIK eye surgery: step-by-step
The surgeon then folds back the hinged flap to access the underlying cornea (called the stroma) and removes some corneal tissue using an excimer laser.
Excimer lasers create a cool ultraviolet light beam to remove (“ablate”) microscopic amounts of tissue from the cornea to reshape it so light entering the eye focuses more accurately on the retina for improved vision.
For nearsighted people, the goal is to flatten the cornea; with farsighted people, a steeper cornea is desired. Excimer lasers also can correct astigmatism by smoothing an irregular cornea into a more normal shape.
After the laser ablation reshapes the cornea, the flap is then laid back in place, covering the area where the corneal tissue was removed. The flap seals to the underlying cornea during the healing period following surgery.
LASIK laser eye surgery requires only topical anesthetic drops, and no bandages or stitches are required.
Before LASIK surgery
Your eye doctor will perform a thorough eye exam to ensure your eyes are healthy enough for the procedure. He or she will evaluate: the shape and thickness of your cornea; pupil size; refractive errors (myopia, hyperopia and astigmatism); as well as any other eye conditions.
The tear film on the surface of your eyes also will be evaluated, and a precautionary treatment may be recommended to reduce your risk of developing dry eyes after LASIK.
Usually, an automated instrument called a corneal topographer is used to measure the curvature of the front surface of your eye and create a “map” of your cornea.
With wavefront technology associated with custom LASIK, you also are likely to undergo a wavefront analysis that sends light waves through the eye to provide an even more precise map of aberrations affecting your vision.
Your eye doctor also will ask you about your general health history and any medications you are taking to determine if you are a suitable candidate for LASIK.
You should stop wearing contact lenses for a period of time advised by your doctor (typically around two weeks) before your eye exam and before the LASIK procedure. This is because contact lens wear can temporarily alter the natural shape of your cornea.
What to expect during LASIK
Before your LASIK surgery begins, numbing eye drops are applied to your eye to prevent any discomfort during the procedure. Your doctor may also give you some medication to help you relax.
Your eye will be positioned under the laser, and an instrument called a lid speculum is used to keep your eyelids wide open.
The surgeon uses an ink marker to mark the cornea before creating the flap. A suction ring is applied to the front of your eye to prevent eye movements or loss of contact that could affect flap quality.
After the corneal flap is created, the surgeon then uses a computer to adjust the excimer laser for your particular prescription.
You will be asked to look at a target light for a short time while your surgeon watches your eye through a microscope as the laser sends pulses of light to your cornea.
The laser light pulses painlessly reshape the cornea, although you may feel some pressure on your eye. You’ll also hear a steady clicking sound while the laser is operating.
LASIK is performed on each eye separately, with each procedure taking only about five minutes.