Keratoconus is an medical condition affecting the eyes which usually develops during the late teens and early twenties. It affects both eyes, but often one before the other. It occurs in about 1 in 3000 people. It is a thinning of the cornea which causes distortion of vision.

Symptoms include:

Causes thought to include eye rubbing, though little is known.

Treatment: Initially, spectacles or a contact lens may be fitted in the affected eye/s. Contact lenses are usually hard (rigid gas permeable), soft, or a hybrid lens. If condition progresses, 1 in 10 people have a corneal transplant.