Corneal cross-linking is a medical procedure designed to strengthen the cornea, the clear front part of the eye. It is primarily used to treat conditions like keratoconus, where the cornea becomes thin and bulges outward. The treatment involves applying a riboflavin (vitamin B2) solution to the cornea and then exposing it to ultraviolet (UV) light, which helps to create new bonds between collagen fibers in the cornea. This procedure can help stabilize the cornea, potentially preventing further vision deterioration. It is typically performed on an outpatient basis and may improve vision in some patients. Recovery time varies, but many people notice improvements within a few weeks.