Keratoconus,characterized by corneal ectasia occurs bilaterally with unknown etiology. Contact lens is the most common way for the mild and modcrate keratoconus. However,epikeratophakia,deep lamellar keratoplasty,intrastromal corneal ring,corneal crosslinking,and penetrating keratoplasty are the surgical way for the keratocous that contact lens could not correct.