Surface ablation
PRK
	Epithelium is pushed or scraped aside and must regrow; moderately significant pain, tearing, photophobia, and blurred vision for the first three to four days
Epithelial LASIK
	Epithelium is removed in a thin flap using a blade (epikeratome) and may be replaced or discarded; more corneal stroma to work with than LASIK; less pain than PRK
LASEK
	Epithelium is removed using alcohol; more corneal stroma to work with than LASIK; less pain than PRK
Stromal flap
LASIK
	Epithelium supported by a thin layer of underlying stroma is removed in a flap (originally with a microkeratome) produced by a cutting laser (femtosecond); less pain than PRK
Lenticule extraction
FLEx
	Femtosecond laser cuts a lens-shaped segment (lenticule) within the corneal stroma, removed through a LASIK-like flap
SMILE
	Similar to FLEx, but the lenticule is extracted through a small laser-cut incision on the edge of the cornea