Keratoconus (KC) is a disorder of the eye which results in progressive thinning of the cornea and in which the clear tissue on the front of the eye (cornea) bulges outward. Its cause is unknown.
Symptoms first appear during puberty or the late teens and include blurred vision, double vision, nearsightedness, astigmatism, and sensitivity to light and glare.
Usually both eyes are affected. In more severe cases a scarring or a circle may be seen within the cornea. Vision can be corrected with glasses or contact lenses early on. Advanced cases may require a cornea transplant