The cornea, the window of the front of the eye, is normally clear. Injury, infection, and aging changes can cause your cornea to lose its clarity and thereby reduce vision.

Some diseases of the cornea are benefited by medical treatment, while other diseases require corneal transplantation, a surgical procedure in which the cornea from a normal eye is used to replace the damaged cornea. In most cases, a corneal transplantation greatly improves vision.