What sort of disease is needing contact lenses?

Keratoconus: Keratoconus, and other corneal diseases with an irregular cornea may benefit from contact lenses as this will give clearer vision than glasses. A contact lens fits directly on the surface, so can even out irregualrities better, as long as the patient tolerates it.

Refractive error: Contact lenses aid the eye in focusing light sharply onto the retina. This allows images to be projected onto the retina clearly, which allows us to see clearly.