Oxygen Flow GP Vs. Silicone Contact Lens

For your eyes to enjoy optimal health, they need to breathe oxygen. While old contact lenses made it difficult for oxygen to reach the eye, gas permeable (GP) contacts and new silicone contacts encourage healthy oxygen flow.

Traditional Soft Contacts

• Because old soft contacts were made from plastic--which blocked oxygen flow to the eye--and water--which quickly dried out--they often gave wearers dry, uncomfortable eyes.

Gas Permeable Contacts

• Since the 1970s, gas permeable contacts with silicone have been in use, allowing oxygen to pass through the lens.

Silicone Hydrogel Contacts

• Many soft contacts are now being made with oxygen-permeable silicone. This means they have a lower water content--since water no longer has to be the primary oxygen carrier for the eye--resulting in less dehydration.

Difference in Oxygen Permeability

• Modern silicone hydrogel contacts are a match for gas permeables when it comes to oxygen flow, because they allow the eye to obtain six to seven times more oxygen than earlier soft contacts.

The Main Difference

• The key difference between gas permeable and silicone contacts is that silicone soft contacts still use some water to transmit oxygen to the eye--meaning they still dehydrate over time--while gas permeable contacts have no troublesome water content.