LASIK Basics

How does LASIK work?

Quick Answer: LASIK works by creating a thin flap in the cornea, then using an excimer laser to reshape the underlying tissue to correct vision problems.

LASIK surgery is a precise, two-step process that permanently reshapes your cornea to correct refractive errors.

Step 1: Creating the Corneal Flap

First, your surgeon creates a thin, hinged flap in the outer layer of your cornea. This can be done two ways:

Bladeless LASIK (Femtosecond Laser): A computer-guided laser creates the flap with extreme precision. This is the most common method today.
Traditional LASIK (Microkeratome): A mechanical blade creates the flap. This method is less common now.

The flap is typically 100-180 microns thick (about the thickness of a human hair).

Step 2: Reshaping the Cornea

Once the flap is created and lifted, an excimer laser reshapes the underlying corneal tissue:

For nearsightedness: The laser flattens the cornea's center
For farsightedness: The laser steepens the cornea's center
For astigmatism: The laser smooths irregular areas to make the cornea more symmetrical

The excimer laser removes tissue at 0.25 microns per pulse—about 1/200th the width of a human hair. Advanced eye-tracking technology follows your eye movements 4,000 times per second to ensure precision.

Step 3: Flap Repositioning

After reshaping, the surgeon carefully repositions the corneal flap. It adheres naturally within minutes and heals without stitches. The entire procedure takes about 10-15 minutes for both eyes.