About Extended Wear Contact Lenses

Extended wear contact lenses are a kind of lens that can be worn overnight. They are convenient because the wearer has perfect vision as soon as she wakes up. However, these lenses involve a number of safety risks.

History

• Extended wear lenses were first approved by the FDA in 1981, according to the All About Vision Web site. The lenses were originally approved for two weeks of continuous wear, but the time was soon extended to 30 days. Researchers soon discovered that people who slept in their lenses had a higher risk of eye infection, so the FDA reduced the wearing period to seven days.

Function

• Extended wear contacts are oxygen-permeable, which means oxygen can pass through the lens to the cornea and allow it to breathe. They are available in rigid gas-permeable and soft materials.

Warning

• People who wear their contacts both day and night have a higher risk of developing eye infections such as giant papillary conjunctivitis, which is an allergic reaction to deposits on the lenses. Other people develop corneal swelling because their eyes do not get enough oxygen during sleep, according to the Contact Lens Docs Web site.