Keratoconus is a corneal ectasia and a disorder in which the cornea is progressively thinning and after a while takes the shape of a cone. The onset of the disease is placed in adolescence, while its progression is rare in the fourth decade of life.

Rubbing the eyes should be avoided, because it is a risk factor for further progression of the disease.

Initially, the correction of the vision is done with glasses or contact lenses.If there is progression, the further treatment of the disease is the collagen cross-linking (CXL) of the cornea.