Keratoconus is a degenerative disease of the most common of the cornea. Is a thinning and deformation, slowly progressive corneal tissue. Since this is the main lens of the eye, this causes myopia and astigmatism evolve toward a loss of vision irregularity and distortion. Keratoconus has been until recently the leading cause of corneal transplantation in our environment, but new techniques such as "rings" intracorneal or crosslinking are in many cases avoiding keratoplasty.