Contact lenses are small plastic
or silicone discs shaped to correct refractive errors.
After your doctor
tests your vision, he or she will write a prescription for the lens you need.
Your prescription may change over time.
Contacts are placed directly on the eye, where they float on a film of
tears in front of the
cornea. Correct design and fitting of the lenses are
essential for comfort, safety, and accurate correction.
Improvements in contact lenses have made them more comfortable and easier
to wear. Millions of people wear contact lenses, and most
wear soft lenses. For these people, contact lenses offer a relatively safe and
effective way of correcting vision problems.
With most hard contact lenses, there
will be a 2- to 4-week break-in period during which you wear the lenses for
increasingly longer periods of time each day. Soft contact lenses usually take
less time to break in.
The care of contact lenses varies according
to the type of lens. Care may range from minimal (disposable extended-wear soft
lenses) to extensive (conventional soft lenses). It is important to follow
directions for lens care carefully to avoid
vision-threatening complications. If you have a hard time following the
cleaning steps, tell your eye care professional. You may be able to simplify
the cleaning steps. Or you may want to switch to disposable lenses.
Contact lenses may be used by people who have had cataract surgery and couldn't have an
artificial lens implanted in the eye.
They may also be used to treat eye diseases, such as
keratoconus or damage to the cornea caused by injury
Most people choose to wear contacts because of the
convenience and because they prefer the way they look without eyeglasses.
Bifocal contact lenses have been developed for people
who have both nearsightedness and
presbyopia. Bifocal lenses provide correction for both
near and distance vision on each lens.
If bifocal contact lenses
will not work for you, your doctor may recommend monovision. With monovision, you wear a contact lens that
corrects for near vision in one eye and a lens that corrects for distance
vision in the other eye. Many people who try monovision
can adjust to it. Monovision has some drawbacks, though. Each eye must work
more independently, making good binocular vision difficult, which can cause
problems with depth perception. You may have to adjust your gaze more often to
allow one eye or the other to see properly.
cases, your doctor may recommend using reading glasses in combination with
contact lenses that correct for distance vision.
People who are
generally well-suited to wearing contact lenses (hard or soft) include:
People who have a lot of trouble seeing
things at a distance and need vision correction all the time. People who wear
eyeglasses only part of the time are less likely to wear contacts
Those with strong motivation. You have to be willing
to tolerate minor discomfort during the break-in period and to learn and use
proper methods of storing and handling your lenses.
People who perform
work or play sports in which glasses are inconvenient or dangerous often choose contacts over glasses.
Contact lenses may not be a
good choice if you:
Are not able or are not willing to care for the
Would have a hard time handling the lenses (for
example, if you have severe arthritis in your hands or another problem that
would make it hard for you to insert, remove, and clean the
Have certain medical conditions such as
uncontrolled diabetes or
asthma, and other chronic respiratory disorders may
make it difficult to wear contacts.
Have dry eyes or problems with
the cornea. People who have
Sjögren's syndrome (a condition that causes a lack of
tears and dry eyes) often are not able to wear contacts. People who have
chronic or recurrent infections or sores on the cornea cannot wear contact
Have a job that exposes you to particles, chemical fumes,
or other vapors that may be absorbed by or stick to the lenses (such as dust
and dirt, paint, spray chemicals, or hair spray).
Infants and children
Infants and children usually
do not wear contact lenses, except to treat some medical conditions. Many
teenagers wear contacts. But they and their parents must accept the need for
frequent changes in the prescription until the eyes stop changing in the late
teens or early 20s.
How Well It Works
Some types work better than others to
correct specific problems. For example:
Rigid gas-permeable lenses may be the best
choice for people who have astigmatism
that's quite high or not normal.
Some people cannot tolerate hard lenses. Soft lenses
that correct both nearsightedness and astigmatism are available. Soft contact
lenses tend to be more comfortable than hard lenses, but hard lenses usually
provide sharper vision.
Some people may choose good (rather than
optimal) vision correction in exchange for greater comfort. People who have severe
nearsightedness or both nearsightedness and astigmatism may get the best vision
correction from gas-permeable lenses. But these people may have satisfactory correction
with soft lenses, which are typically more comfortable.
Minor but bothersome side effects of contact
lenses are common. But the overall risk of infection and other
vision-threatening complications is low.
Problems sometimes caused
by wearing contact lenses include:
Inflammatory bumps can form under the eyelid, making it uncomfortable to wear
Some problems are more common with certain types of lenses.
You may be able to avoid some problems by
cleaning your lenses more often, not wearing your
lenses overnight or, in some cases, changing the type of lenses you
What To Think About
After going through the time and
expense of fitting contact lenses, some people find that they are not able to
wear them. Allergies, dry eyes, discomfort during the adaptation period, and
the "hassle factor" are frequent causes of not being able to wear
It may take time to find the type of contact lens and a
wearing schedule that is best for you. A wide variety of lenses is available.
When you choose a lens, think about cost, comfort, quality, cleaning time, and safety. Look for an eye care professional who is willing
to work with you to select the best type of lens for your needs and lifestyle.
Many people have problems with their contacts because they don't follow
instructions on wearing time, disinfection, and other cleaning and care
practices. For best results and to protect your eye health, follow all instructions closely.
Daily disposable lenses are the
safest soft contact lenses for your eyes.
How this information was developed to help you make better health decisions.