LASIK is a laser procedure that reshapes the cornea — the clear front surface of the eye — so that light entering the eye focuses properly on the retina. It corrects the common focusing errors: nearsightedness (myopia), farsightedness (hyperopia), and astigmatism. The site's ophthalmology collection includes a full LASIK procedure video, embedded above, that shows the steps described here.

The idea in one paragraph

Vision blurs when the eye's shape bends light to the wrong spot. Glasses and contact lenses bend the light before it enters the eye; LASIK instead changes the eye itself, removing microscopic amounts of corneal tissue with a precisely controlled laser so the cornea's curve is corrected permanently.

The procedure, step by step

1. Numbing and preparation. Numbing drops are placed in the eye; no injections or general anesthesia are involved. A small holder keeps the eyelid open.

2. Creating the flap. The surgeon creates a thin flap in the surface of the cornea — either with a femtosecond laser or a precision blade (microkeratome) — and folds it gently back, like opening a tiny door.

3. Reshaping the cornea. You look at a target light while an excimer laser removes tissue from the exposed corneal bed, point by point, following a map computed from your eye measurements. An eye tracker follows small eye movements throughout. This step usually takes well under a minute per eye.

4. Replacing the flap. The flap is laid back into place, where it adheres naturally within minutes — no stitches. The other eye is then treated the same way.

The whole visit is short — the laser work itself takes minutes — and most people notice much clearer vision within the first day, with eyes often feeling gritty or dry for the first days to weeks.

Who it generally suits — and who it doesn't

LASIK is generally considered for adults whose glasses prescription has been stable, whose corneas are thick enough and healthy, and whose eyes are free of diseases such as keratoconus or severe dry eye. It is not performed during pregnancy, and some prescriptions are simply too strong or corneas too thin — which is why a proper screening exam, not the procedure day, is where the real decision happens. For people who don't qualify, alternatives such as PRK or implantable lenses exist.

Educational only — this article is general information about how LASIK works, not medical advice and not an assessment of whether it suits your eyes. Only a screening examination can determine that.

Frequently Asked Questions

Does LASIK hurt?

The eye is numbed with drops, so most people feel pressure rather than pain during the procedure. Mild irritation, grittiness, and dryness are common for days to weeks afterwards.

How long does LASIK last?

The corneal reshaping is permanent, but eyes continue to age — reading glasses are still typically needed in the forties and beyond (presbyopia), and a small number of people later choose an enhancement procedure.

How soon can I return to work?

Many people return to desk work within a day or two, with eye drops and follow-up visits as instructed, and temporary restrictions on swimming, eye rubbing, and contact sports.

What are the main risks?

Dry eyes, glare or halos at night (usually temporary), under- or over-correction, and flap-related issues are the commonly discussed ones. Serious complications are uncommon, and screening exists precisely to keep unsuitable eyes out of the procedure.