Extended Wear Contact Lenses - Are they safe?
Determining whether overnight contact lenses are safe to use
Contact lenses are made for two different wear schedules: the first is daily wear, meaning you remove them
before sleeping, and the second is extended wear, or overnight wear. The United States’ FDA has approved some
contact lenses for daily wear only, and others for extended wear. Extended wear lenses can be distinguished from
other lenses easily because they allow more oxygen to reach your eye's cornea.
Most FDA-approved extended wear lenses are meant to be worn without removal for up to seven days. Certain lenses
made of a new type of soft contact lens material, silicone hydrogel, is considered "super-permeable," and these new
lenses may approved for up to 30 days of wear without removal. One gas permeable lens brand is also approved for 30
days of wear. Extended wear that lasts up to a month is referred to as continuous wear.
Extended Wear Contact Lenses: A Brief History
What you might not know: the FDA first approved overnight wear of contact lenses in 1981. Initially, these lenses
were to be worn for up to two weeks without removal and 30-day approvals came shortly thereafter. However,
researchers quickly found that people who slept in their contact lenses were much more susceptible to eye
infections. In response, the FDA changed the maximum extended wear period to seven days. Eye-care doctors soon
decided that any overnight wear for contact lenses was too risky and discouraged patients from overnight
wearing.
The eye-care practitioners were concerned about potentially dangerous organisms, which might enter your eye from
your fingers, your eyelids, or the lens care solutions you use, and eventually get lodged under your lens. These
organisms can thrive better if the oxygen supply to your eye is reduced through covering it and if your contact
lens is not removed nightly. This might lead to infections that range from an annoying case of conjunctivitis to
more serious conditions that can lead to blindness.
Extended Wear Lenses Comeback
Today, overnight wear of contact lenses is more commonplace and less taboo. What has changed?
The introduction of disposable contacts helped address some of the health concerns about extended wear. Extended
wear lenses were previously removed weekly, but they were re-used week after week, for months. Although lenses were
cleaned with some type of lens care system, reusing the same lens meant that it was impossible to clean out all the
proteins, lipids, and other deposits that collected on the lens. These deposits formed a potential breeding ground
for germs and caused inflammation and discomfort.
Nowadays, extended wear lenses are typically disposable. If you sleep in your lenses, you throw them out each week
and start with a fresh pair. This has the advantage of avoiding long-term deposit buildup and promoting eye
health.
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