LASIK eye surgery is a refractive surgery intended to reduce a patient's dependency on eyeglasses or contact lenses. LASIK is the most prevalent of all refractive surgery types. LASIK aims to reshape the cornea in order to allow for accurate refraction, which results in the light rays falling exactly on the retina (a series of light sensing cells). This enables crystal clear vision.

In general, common refractive errors, such as nearsightedness, farsightedness and astigmatism are caused due to the irregularities of the corneal surface. These anomalies can be corrected by reshaping the cornea. LASIK procedure makes use of an advanced laser called excimer, which is an ultraviolet chemical laser. The laser is controlled by sophisticated computer software. The computer-controlled sensors measure the eye position a few thousand times per second, and then redirect the laser to make precise incisions in the cornea. The reshaped cornea allows for the desired refraction and therefore results in enhanced visual acuity.

Conventional LASIK procedure makes use of a microkeratome, a diminutive surgical blade, to cut a flap in the corneal surface. However, variations of the traditional LASIK procedure may employ a laser to accomplish the same. Whatever may be the procedure to cut the flap, after it's done, the excimer laser is used for precise ablation of the stroma - the middle layer of the cornea. The flap is then folded back so as to act as a natural bandage. The cornea may take a few days to heal. During this period, the patient may experience blurry vision and certain minor side-effects like halos or glare. However, these complications normally subside within a few days or weeks, when the cornea has completely healed.

Other common types of surgery, apart from traditional LASIK, are photorefractive keratectomy (PRK), radial keratotomy (RK), and LASEK. There is also a rather new procedure and it can be considered as an enhancement of the traditional LASIK procedure. It is called custom LASIK or wavefront-guided LASIK. It is a more advanced procedure and is capable of treating other vision impairments as well, apart from the common vision disorders specified above.