LASIK surgery reshapes your cornea using two lasers in a procedure that typically takes less than 30 minutes for both eyes, with each eye requiring only seconds of actual laser contact. The process has three core steps: creating a thin flap on the surface of your cornea, reshaping the tissue underneath to correct your vision, and repositioning the flap to heal on its own. Within six months, more than 90% of patients achieve 20/20 vision or better.
Before Surgery: Mapping Your Eyes
The procedure starts well before you enter the operating room. Your surgeon needs a precise, three-dimensional map of your cornea’s surface, which is unique to your eye the way a fingerprint is unique to your finger. Computerized instruments called videokeratoscopes project rings of light onto your cornea and digitize thousands of surface points to produce detailed, color-coded maps of its curvature. More advanced systems like the Pentacam use rotating camera imaging to directly measure the elevation and depth of your cornea, generating a full thickness map that identifies the thinnest point and compares it to the center.
These measurements determine exactly how much tissue needs to be removed and where. Your surgeon also confirms you have enough corneal thickness to safely create the flap and still leave a structural reserve underneath. Your prescription needs to have been stable (changing no more than half a diopter) for at least a year before surgery. LASIK can correct nearsightedness up to about -12.0 diopters, farsightedness up to +6.0 diopters, and astigmatism up to 6.0 diopters.
Step 1: Creating the Corneal Flap
On the day of surgery, numbing drops are applied to your eyes. You’re fully awake the entire time. The first step is creating a thin, hinged flap on the front surface of your cornea, which your surgeon will lift to access the tissue underneath.
There are two ways to make this flap. The older method uses a mechanical microkeratome, a precision instrument with a tiny oscillating blade attached to a suction ring. The ring holds your cornea under pressure while the blade passes across it, creating the flap in under 30 seconds. The newer, more common approach is “bladeless” LASIK, which uses a femtosecond laser. This infrared laser fires ultrashort pulses of energy into the cornea at a precise depth, creating thousands of microscopic bubbles (each only 2 to 3 cubic micrometers) arranged in a flat plane. These tiny bubbles separate the tissue at a molecular level, defining the boundary between the flap and the bed beneath it. The laser then stacks bubbles vertically around the edges to complete the side cut.
The femtosecond laser portion takes about 15 to 20 seconds, though the total time with suction on runs 30 to 45 seconds. Once the flap is created by either method, your surgeon gently folds it back to expose the underlying corneal tissue called the stroma.
Step 2: Reshaping the Cornea
This is where your vision actually gets corrected. A second laser, called an excimer laser, delivers pulses of ultraviolet light at a wavelength of 193 nanometers. At this wavelength, the corneal tissue absorbs energy intensely, and each pulse vaporizes a microscopic layer of tissue with almost no heat damage to surrounding areas. The process is called ablative photodecomposition: the UV energy breaks molecular bonds in the tissue, and the material essentially disappears as a gas.
For nearsightedness, the laser flattens the center of the cornea so light focuses correctly on the retina instead of in front of it. For farsightedness, it steepens the central cornea by removing tissue from the edges. For astigmatism, it smooths out an irregularly shaped cornea into a more uniform curve. The pattern of tissue removal is programmed into the laser’s computer based on the maps taken during your pre-operative exams.
Standard vs. Wavefront-Guided Treatment
Standard LASIK corrects basic refractive errors: nearsightedness, farsightedness, and astigmatism. Wavefront-guided (or “custom”) LASIK goes further by also addressing higher-order aberrations, which are subtle optical irregularities that can reduce contrast sensitivity, create halos around lights, or degrade night vision. A wavefront sensor maps the unique imperfections in how light travels through your entire optical system, and the excimer laser uses that map to deliver a more personalized correction. The latest wavefront-optimized platforms have shown strong results, with one recent study reported by the American Academy of Ophthalmology finding that 98% of patients achieved 20/12.5 vision or better.
Step 3: Repositioning the Flap
After the excimer laser finishes, which takes only seconds per eye, your surgeon folds the corneal flap back into its original position. No stitches are needed. The flap self-adheres naturally within just a few minutes due to the natural suction between the wet tissue surfaces. Over the first day or two, the outer layer of your cornea (the epithelium) seals the edges of the flap. Over the following weeks, natural bonding substances within the cornea gradually anchor the flap to the tissue beneath it.
What Recovery Looks Like
You’ll need someone to drive you home. Your surgeon will likely tell you to go straight home and nap, keeping your eyes closed and rested for the remainder of that first day. No screens, no reading, no work that evening.
The improvement is fast. Most people can drive safely within a day and return to work and normal activities within 24 to 48 hours. Your vision may not be perfectly sharp in those first couple of days, but it will be close, and it can continue refining for up to six months. You’ll use prescription eye drops and preservative-free artificial tears at least four times daily for the first few weeks to support healing and manage dryness.
Activity restrictions are straightforward: no exercise for three days, no eye makeup or skincare products near your eyes for two weeks, no contact sports for a month, and no swimming pools or hot tubs for one to two months. These timelines protect the healing flap from being dislodged or exposed to bacteria.
Risks and Side Effects
Dry eye is the most common side effect in the weeks following LASIK, which is why artificial tears are part of the standard recovery plan. Some people experience halos, glare, or reduced night vision, particularly in the early healing period. These symptoms typically fade as the cornea stabilizes.
The most serious rare complication is corneal ectasia, a progressive weakening and bulging of the cornea that can significantly affect vision. Reported incidence ranges from 0.04% to 0.6%. Thorough pre-operative screening, especially corneal thickness mapping that identifies the thinnest point, is specifically designed to catch eyes at risk for this before surgery ever happens.