Gas permeable lenses are made of a non-pliable breathable material that retain their shape on the eye. This unique feature allows the contacts to replace the irregular surface of the eye with a smooth, uniform surface to achieve improved vision over soft contact lenses and eye glasses. Occasionally a technique called “piggybacking” may be used to improve comfort. This technique utilizes a soft contact lens on the cornea to cushion the gas permeable lens. Your doctors are highly trained in different designs for an optimal fit.