Scleral Lens Overview, Types, Cost, Special-Effect and Problems

What are Scleral Lenses?
Scleral lenses are large diameter rigid gas permeable lenses that range from 14 mm to over 20 mm in diameter. They are termed “scleral” lenses because scleral lenses completely cover the cornea (the clear dome of tissue that covers the colored part of the eye) and extend onto the sclera (the white part of the eye that forms the outer wall of the eye).