LASIK (Laser Assisted Intrastromal Keratomileusis). This surgery consists in creating a flap on the surface of the cornea with a femtosecond laser, and removing with an Excimer laser a micro-thin layer of corneal tissue beneath the flap, according to the anomaly to treat (myopia, hyperopia, astigmatism or presbyopia). The flap is then replaced. The new curve of the cornea allows a correct positioning of the image on the retina. Here, femtosecond laser beeing used.