FS laser technology has been discovered in the late nineties. As an advancement from pico and nanosecond lasers, it gives ultra-short pulses. The wavelength of this laser is 1 µm in the infrared range. This gives the advantage of a more precise surgical effect. The FS laser produces its effect in tissues through the formation of cavitation bubbles.Currently, four available machines use the FS laser system. The earliest is the Intralase FS laser system ,which has been introduced in 2002. Other machines introduced subsequently include Femtec, Visumax and Femto LDV. The last 2 machines give the advantage of combining the FS laser applanation head and the excimer laser head into the same machine ,so the patient will not have to move from table to table within the operating theatre.