Corneal crosslink through UVA-riboflavin photochemistry has been shown to be an effective treatment for keratoconus, related keratectasias and infectious melting keratitis that did not respond to systemic therapy. It is a new approach to increase the mechanical and biochemical stability of the stromal tissue. The purpose of this paper is to review the basic principle, procedure, laboratory and clinical researches about corneal crosslink. In the current situation, it can state only that UVA-riboflavin induced corneal crosslink leads in the majority of the cases to a halt of the progression, and the complications of the corneal endothelial cells, crystalline lens and retina seem to be rare.