Femtosecond (intralasik) laser technique involves the thin membrane layer found at the front part of the cornea to be lifted, prior to the application of excimer laser, not using a mechanical microkeratome device, but using a laser light specifically developed for this procedure.
The basis of this method is the same as Lasik. The only difference being the opening of the corneal membrane using laser. Firstly, the flap is lifted using a Femtosecond laser, in the second stage excimer laser is applied to the underlying tissue. The advantage of this method, is that it allows for a membrane as thin as 100 microns to be lifted.