rigid gas permeable (RGP) contact lens, a contact lens made of rigid plastic that transmits oxygen to the cornea, which makes the lens more comfortable to wear. In comparison with soft lenses, RGP lenses hold their shape better and offer clearer vision, are more durable, and are less prone to harbor bacteria and protein deposits. However, they cause discomfort on initial wearing and require a short adaptation period. Also called gas permeable contact lens.