LASIK is performed as an outpatient procedure under topical anaesthetic eye drops, taking approximately fifteen minutes per eye. A thin corneal flap of approximately ninety to one hundred microns is created using either a femtosecond (bladeless) laser or a mechanical microkeratome. The flap is folded back to expose the corneal stroma, which is then ablated by an excimer laser according to a pre-calculated treatment map derived from wavefront aberrometry and corneal topography measurements. The flap is repositioned over the treated surface and adheres without sutures by virtue of natural surface tension.
Candidacy depends on stable refraction for at least twelve months, minimum corneal thickness (typically above 480 to 500 microns) with adequate residual stromal bed after ablation, and corneal topography showing no signs of pre-existing ectasia or keratoconus. Patients with very high refractive errors, dry eye disease, or irregular corneas may be better served by alternative procedures such as photorefractive keratectomy (PRK), SMILE, or phakic intraocular lens implantation.
Visual recovery after LASIK is characteristically rapid: most patients achieve functional vision within twenty-four hours and notice a marked improvement within the first day. The review appointment at twenty-four to forty-eight hours is important for confirming flap position and early visual acuity. Most patients are advised to use preservative-free lubricating drops for several months to manage the transient dry eye that is nearly universal post-LASIK. Night vision disturbances (halos, starbursts) are common in the first weeks and typically improve over three to six months.