How LASIK works
A femtosecond laser (or, in older platforms, a microkeratome) creates a thin flap of corneal tissue, about a tenth of a millimetre thick, which is gently lifted like a page. An excimer laser then removes microscopic amounts of tissue from the exposed bed — flattening for myopia, steepening for hyperopia, and selective shaping for astigmatism — following a map derived from your measurements. The flap is repositioned, where it adheres without stitches within minutes. The whole laser portion takes seconds per eye.
Who is a good candidate
The essentials: age 18 or above; a stable prescription for about a year; sufficient corneal thickness and a healthy, regular topography (no keratoconus); healthy tear film; normal eye pressure and retina; and realistic expectations. LASIK treats a broad range of myopia, hyperopia and astigmatism, but every degree of correction consumes tissue — which is why thickness measurements, not desire, set the ceiling.
LASIK vs SMILE vs PRK
LASIK offers the fastest visual recovery and easiest early comfort. SMILE avoids the flap through a keyhole lenticule extraction. PRK avoids any flap at all, at the cost of several extra days of surface healing. For many candidates more than one option is safe; where that happens, lifestyle, profession and personal preference complete the choice.
Recovery and aftercare
Most patients see usefully within hours and return to routine activity in a day or two. Drops cover antibiotics, steroids and lubrication over the following weeks. Early cautions: no eye rubbing, keep water and cosmetics away briefly, and use protective eyewear for contact sport per advice. Night halos are common in the first weeks and usually fade; dry-eye symptoms, if they appear, are managed until the surface settles.
Risks, stated plainly
LASIK is among the most studied elective surgeries in medicine, with high satisfaction in appropriately selected patients. Honest counselling still includes: dry-eye symptoms (usually temporary), night-time halos and glare, under- or over-correction (enhanceable in many cases), flap issues (rare), and the small long-term consideration of ectasia — progressive corneal weakening — which strict candidacy screening exists to prevent. Eyes with suspicious topography are declined, not treated.