The outer covering of the colored part of your eye is called the cornea. The cornea is the front window of the eye. The normal cornea is round in shape and clear like a window; however, in keratoconus it is cone-shaped. When the cornea is cone-shaped, people have trouble seeing. The cornea can scar with this condition. Nobody knows the cause of keratoconus, but many scientists believe genetics plays a role.
With mild keratoconus, people can see with their glasses. However as the keratoconus progresses, the astigmatism in their prescription gets higher and more irregular. As this happens, the only way people can see is with a hard contact lens. If the condition is severe with scarring, only a corneal transplant procedure can help gain better vision.
© American Academy of Ophthalmology