Keratoconus, its abbreviation is KC, is a progressive eye disease that the round cornea becomes thin and begins to bulge to a cone shape. It brings highly irregular nearsightedness and various degrees of damage of eye vision. KC would occur in both eyes in early 20s, the cause of KC is not found exactly. However, there are a few methods can be used for treating KC. The light KC can be treated by medicine, eyeglasses or soft contact lenses. The RGP (Rigid Gas Permeable) lenses are a good method for treating the KC. But some patients aren't comfortable about the contact lenses. Maybe the corneal inserts can fit for those patients to get flatter cornea and clearer vision.