Topic Overview
To avoid eye problems, be sure to follow the directions for cleaning and wearing
contact lenses. Contact lens wearers have an increased
risk for serious eye infections and injury to the
. Contact lenses can cause eye problems, such as
damage to the cornea or eye infections. Small objects that get into the eye may
become trapped under a lens and scratch the cornea. Pinkeye () or other minor eye infections are
likely to irritate your eyes and make wearing contacts uncomfortable and
unsafe.
Symptoms of possible problems with contacts
include redness, pain or burning in the eye, drainage, blurred vision, or
sensitivity to light ().
If you are having problems, remove your lenses and disinfect them. If you have symptoms
longer than 2 to 3 hours after removing and cleaning your contacts,
call your eye doctor.
Soft lenses
- Daily-wear lenses are
removed and cleaned at night and reinserted in the morning. They take less time
to get used to than hard lenses, but they are less durable.
- Extended-wear lenses can be worn for up to a week at a time,
day and night. They are then removed, cleaned, and reinserted. But some people
cannot tolerate the extended wear. Their eyes become irritated if the contacts
are not regularly removed and cleaned. Extended use may be uncomfortable, and
it increases the risk of damaging the eye. Many eye
doctors () recommend that you take your contacts out while you
sleep.
- Disposable lenses (daily and extended-wear) were designed to
be worn for up to several weeks and then discarded. Many new contact lens
wearers now choose disposable lenses. Disposable lenses were introduced because
it was thought that replacing lenses more often would reduce the risks of
(infectious or bacterial
keratitis), a dangerous complication of soft lenses. But later studies have
shown that people who wear disposable lenses, especially the extended-wear
kind, may have a higher risk of keratitis.
Hard lenses
- Conventional hard lenses (PMMA) are made of a stiff plastic (polymethyl methacrylate, or PMMA),
which does not mold to the shape of the eye. These lenses correct vision with
no distortion, and they are durable. But they
are the least comfortable type of contact lens. Because they reduce the amount
of oxygen reaching the cornea, people who wear them are at risk of overwearing
syndrome and other problems.
- Rigid gas-permeable (RGP) lenses are somewhat less durable, but they
are more comfortable than conventional hard lenses. Some gas-permeable lenses
are designed for extended wear (overnight, up to 7 days). But many eye
specialists advise against wearing them for the extended period, because there is a small risk of severe infection.