What are gas permeable contact lenses?
Gas permeable contact lenses are small, curved pieces of durable, slightly flexible plastic shaped to fit your eyes. They float on the tear film in front of the cornea (the clear outer layer on the front of the eyeball). Contacts lenses work the same way that glasses do to improve your vision. The plastic used for gas permeable lenses allows oxygen to reach the cornea. The original hard contact lenses, which were made of a plastic that did not allow oxygen to reach the cornea, are rarely prescribed today. Although gas permeable lenses are not the same as the hard lenses of the past, people sometimes still refer to gas permeable lenses as “hard” or “rigid” lenses. This is because they are harder and more durable than soft contact lenses. Because of improvements in materials used to make them, gas permeable lenses have several advantages over soft lenses and are being prescribed more frequently.
