Rigid Gas Permeable Contact Lenses
Rigid gas permeable ("RGP" or "GP") contact lenses offer many advantages over soft contact lenses. GP lenses generally provide sharper vision (especially if you have astigmatism) and they allow more oxygen to reach your corneas, potentially reducing the risk of infections and other eye health problems. Rigid gas permeable contact lenses are also more durable than soft contact lenses, often lasting well over a year. And unlike soft lenses, RGP contact lenses are custom-fit, base on the exact measurements of your eyes.
Despite these advantages, only about 5% of contact lens wearers choose GP lenses. Even though the long-term comfort of gas permeable contacts is equal, if not better, than that of soft contact lenses, GP lenses are initially somewhat uncomfortable. It can take several weeks for your eyes to adapt to the lenses before they feel comfortable. (Soft contact lenses, on the other hand, are usually comfortable within a day or two.)
Gas permeable lenses, however, are typically the best choice if you want the sharpest vision possible from contact lens wear. For people who want the clarity of GP lenses but cannot wear the lenses comfortably, there are now hybrid contact lenses that have a GP center, surrounded by a soft lens periphery. These lenses may be able to offer you the clarity of a GP lens with comfort that comes close to soft lenses.
GP lenses remain the contact lens of choice for the treatment of an eye condition called keratoconus. In keratoconus, the cornea develops an irregular shape and vision cannot be corrected to acceptable levels with eyeglasses or soft contact lenses.
Gas permeable lenses are also used in a non-surgical vision correction technique called orthokeratology, or "ortho-K."