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Extended Wear Contact Lenses
Contact lenses are available for two different wear schedules:
daily wear and extended wear. What distinguishes extended
wear lenses is that they allow more oxygen to reach the
eye's cornea. Soft contact lenses are made of plastic materials
that incorporate water. Extended wear contact lenses are
made of a material designed to last two to four weeks.
The water makes extended wear contacts soft and flexible
while allowing oxygen to reach the cornea. Most extended
wear lenses are FDA approved to be worn without removal
for up to seven days. Many people are able to wear extended
wear contacts continuously for many days with no apparent
problem or complication. However, sleeping in contact lenses,
while convenient, could substantially increase the risk
for infection and other complications. The oxygen supply
to the cornea drops overnight while wearing a contact lens.
A new generation of contact lenses is making 30-day contact
lens wear safer. These continuous wear lenses are made from
new super-permeable silicone hydrogel materials. The lenses
provide much more oxygen to the eye than most conventional
extended wear contact lenses, in some cases allowing six
times more oxygen to pass through to the cornea than typical
disposable lenses. The new lenses also repel bacteria much
better than older materials.
Proper Care is Critical
People who choose extended wear lenses can reduce their
risk of infection by following an eye doctor's instructions
for replacing and caring for the lenses. Studies show that
a large percentage of infections and other complications
are directly related to improper cleaning and disinfecting.
One option that works well for some wearers is to use extended
wear lenses on a daily wear basis, with occasional overnight
wear. This can be helpful if someone doesn't want to remove
lenses to take a nap, or if they want to sleep in lenses
only occasionally, such as on a weekend trip.
Another way to avoid a problem with extended wear lenses
is to consult an eye doctor with early signs of irritated
or red eyes or reduced vision.
Not everyone can get fitted properly with the new lenses.
Some lenses are not yet made to correct astigmatism, an
inability of the eye to focus sharply due to an abnormally
shaped cornea. And they are not yet available as disposables,
although industry experts expect they will be in the future.
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