In ReLEx® the VisuMax femtosecond laser creates two interfaces that define a refractive lenticule of stromal tissue. In ReLEx® FLEx, the upper interface is converted into a LASIK flap by the creation of a sidecut. The LASIK flap is lifted and the lenticule can be removed to correct the refractive error by tissue subtraction. In ReLEx® smile, the lenticule is dissected and removed through a small 2-3mm incision without the need to create a whole flap.