A condition in which the clear tissue on the front of the eye, called the cornea, gets thinner and bulges outward.
With keratoconus, the clear, dome-shaped tissue that covers the eye, called the cornea, thins and bulges outward into a cone shape. Its cause is unknown.
Symptoms first appear during puberty or the late teens and include blurred vision and sensitivity to light and glare.
Vision can be corrected with glasses or contact lenses early on. Advanced cases may need a cornea transplant.