Gas permeable contacts

Gas permeable contact lenses are durable lenses that have a very long life expectancy. They are very kind to the eye, since they allow oxygen to pass through. Although made with a hard material, they have very little in common with the early hard lenses made of PMMA, which were quite tough on the eye and hard to get used to.

Oxygen permeable lenses are made of silicone, a material that's more flexible than PMMA. It allows oxygen to enter the eye to an even higher degree than soft contact lenses.

The rigid material of gas permeable contacts produces a better visual acuity. For example, the lens doesn't deform when you blink. It also offers better resistance against the build-up deposits of proteins, calcium and other minerals from your tears. Plus, harder lenses have a much longer life span. They are easy to clean, and when well taken care of, can last for years. This usually makes them less expensive in the long run.