*Fundamentals of Femtosecond Laser and Its Application in Ophthalmology DOI: http://dx.doi.org/10.5772/intechopen.106701*

procedure (Carl Zeiss Meditec AG), the intrastromal lenticule is sculpted for correction of myopic or astigmatic refractive error; during this procedure, FSL is used for the anterior and posterior dissection of both faces of the refractive lenticule in addition to the small incision in the mid-periphery of the cornea for safe extraction of the intrastromal lenticule. Other companies introduced their own laser systems later, such as SmartSight by Schwind and corneal lenticule extraction for advanced refractive correction by Ziemer Ophthalmic Systems AG. Research is continued to determine the superiority of FS-LASIK over RELEX and SMILE [ 4 , 5 , 14 , 15 ].

 When corneal incisions are used to treat astigmatism, Fs-technology allows for exceptional precision and control over all aspects of the keratotomy procedure. Fs-specific intrastromal keratotomies, on the other hand, reduce the risk of infection by avoiding open wounds.
