First, a circular ring is centered on the cornea and held in place via vacuum. The vacuum causes a pressure sensation and temporarily dims the vision. In order to help confirm proper vacuum, many surgeons will pause to ask the patient whether the vision is dark and a pressure sensation is present.

Once adequate vacuum is achieved, the microkeratome is attached to the ring and passed across the surface of the cornea to create the flap. Because the vision is dark, this step is not visible to the patient.

After the microkeratome pass, the vacuum is released, the circular ring is removed and the flap is lifted to expose the stromal bed.

Lifting of the LASIK flap.

The laser treatment usually lasts anywhere from a few seconds up to a minute, depending on the amount of correction.

Afterwards, the treated area is rinsed and the flap is smoothed back into place, where natural adhesive forces seal it down.

The LASIK flap is now back in place.