cataract is a painless, cloudy area in the lens of the eye that blocks the
passage of light to the retina. The retina is the nerve layer at the back of
the eye. The nerve cells in the retina detect light entering the eye and send
nerve signals to the brain about what the eye sees. Because cataracts block
this light, they can cause vision problems.
What causes cataracts?
Aging and exposure to
sunlight can cause cataracts. Changes in your eyes are often a normal part of
aging. But the changes do not always lead to cataracts.
also happen after an eye injury, as a result of eye disease, after you use
certain medicines, or as a result of health problems such as
Sometimes children are born
What are the symptoms?
Cataracts can affect your
You may have cloudy, fuzzy, or foggy vision.
may see glare from lamps or the sun. You may have trouble driving at night
because of glare from car headlights.
You may need frequent
changes to your eyeglasses prescription.
You may get double vision
in one eye.
Your near vision may improve for a short time if you
get a cataract. This temporary improvement is called
The vision loss from a cataract often happens slowly
and may never become severe. Sometimes cataracts do not cause any vision problems.
How are cataracts diagnosed?
Your doctor can find
out if you have cataracts by doing a physical exam and by asking questions
about your symptoms and past health. You may need tests to make sure you
have a cataract or to rule out other conditions that may be causing vision
How are they treated?
Surgery can remove cataracts. For most adults, surgery is only needed when vision
loss caused by a cataract affects their quality of life.
There are a number of things you can
do that may help you manage your vision problems. Many people get along very
well with the help of eyeglasses, contacts, or other vision aids. Keep your
eyeglasses or contact lens prescription up to date. Also make sure you have
plenty of lighting in your home. You may be able to avoid or delay
Whether you need cataract surgery depends on how much of
a problem the cataract causes for daily activities like driving and reading.
Surgery is almost always by your choice (elective) and can be scheduled when it
is convenient. For people who decide to have surgery, the surgery usually
works very well.
Some people have to have surgery. Children are
sometimes born with cataracts that need to be removed. Other people may get
cataracts after an eye injury or as a result of eye disease or other health
problems. Cataracts from these causes may also need to be removed.
How can you prevent cataracts?
There is no proven
way to prevent cataracts. But there are some things you can do that may help
slow cataract growth. Don't smoke. Wear a hat or sunglasses when you are in
the sun. And avoid sunlamps and tanning booths. Eat healthy foods. And keep diabetes under control.
As a cataract progresses, more of the lens becomes cloudy.
When the entire lens is white, the cataract is called a "ripe" or "mature"
cataract and causes severe vision problems. Delaying surgery until cataracts
are ripe or mature is neither recommended nor needed.
Cataracts in children are rare but serious. If a cataract prevents light from
entering a child's eye and stimulating the retina, the area of the brain used
for sight does not develop properly. Usually the child won't see well with
that eye (amblyopia), even if the cataract is later
What Increases Your Risk
Things that increase your risk for
Age. Getting older is a
major risk factor for cataracts.
Family history (genetics). People with a
family history of cataracts are more likely to have
cataracts. People with certain
genetic disorders may also have an increased risk for
Some chronic diseases increase the risk for cataracts.
Keeping these diseases under control may help lower your risk for
People with diabetes are at increased risk for cataracts. Damage to the lens of
the eye results from persistent high blood sugar (glucose) levels.
to treat glaucoma may raise the risk of cataracts.
Other things that may increase your risk include:
Smoking. People who smoke are more likely to
develop cataracts. Smoking may damage the lens of the eye by leading to the
formation of chemicals called
free radicals. High levels of free radicals can damage
cells, including those in the lens of the eye.
Infection during pregnancy. If a woman has certain
infections during pregnancy, such as
chickenpox, the baby may develop a cataract before
Speak with an
ophthalmologist about surgery to remove cataracts. In
most cases, you can decide if you want or need surgery based on whether vision
problems caused by the cataract are interfering with your daily
Who to see
The following health professionals can evaluate
vision problems that may be caused by a cataract:
When you are deciding whether to have
surgery, you may find it very helpful to evaluate the effect that vision loss from a
cataract has on your life. Your doctor may ask you to complete a questionnaire
regarding the effect of the cataract on your daily activities.
already have some vision loss that cannot be corrected by cataract
surgery, your doctor may do a
low-vision evaluation to help find ways for you to
make the most of your remaining vision and to keep your quality of life.
eye exams, your eye doctor will look for early signs of vision
problems, including cataracts.
Testing your child for cataracts may be needed if
you think your child is having a vision problem.
Surgery is the only
effective method of treating vision loss caused by
Cataract surgery is a common
procedure that involves removing the clouded lens of the eye (the cataract).
The lens makes it possible for the eye to focus. The lens can be replaced with an artificial
lens called an
intraocular lens implant (IOL). Sometimes an IOL is not used, and eyeglasses or contact lenses can compensate for the lens that is removed.
Surgery is often not needed or can be delayed for months or years.
Many people with cataracts get along very well with the help of eyeglasses,
contacts, and other vision aids.
Sometimes a cataract needs
to be removed because of another eye disease, such as
diabetic retinopathy or
macular degeneration. In some cases the cataract has
to be removed so that the eye specialist can treat the retina, the nerve layer
at the back of the eye.
Misconceptions about cataracts are common.
More and more medical centers have been built specifically
for cataract surgery. Marketing campaigns aimed at older adults may encourage
some people to have surgery when they do not really need it. Because of fear of
blindness or loss of independence, older adults may think they need to have
surgery even when their cataracts do not affect their quality of life. In many
cases, wearing eyeglasses or contacts and using other vision aids might be
appropriate and just as effective without any of the risks of surgery.
Only you can decide whether a cataract is affecting your vision and your
life enough to have surgery. If surgery is not going to improve your vision,
you may decide that surgery is not for you.
There is no proven way to prevent
cataracts. But certain lifestyle habits may help slow
cataract development. These include:
Wearing a hat or
sunglasses when you are in the sun.
Avoiding sunlamps and tanning booths.
Eating healthy foods.
Avoiding the use of
steroid medicines when possible (some people need them).
Low-vision aids and adaptive technologies such as
video enlargement systems or speech software for computer systems can help
people who have impaired vision make the best use of their remaining vision.
Evidence shows that making certain lifestyle changes
such as not smoking and protecting your eyes from sunlight may help slow the
development of cataracts.
After cataract surgery
Your doctor will give you
instructions about what to do after cataract surgery.
Eye care for adults after cataract surgery includes using prescribed
eyedrops, protecting your eye, and watching for signs of infection.
Contact your doctor promptly if you notice any signs of complications,
It is normal to have blurred vision and some swelling
after surgery. It takes time for the swelling to go down. Your eyeglass
prescription may change after surgery.
A small number of adults and children with
cataracts may benefit for a short time from eyedrops
that widen (dilate) the pupil. These eyedrops increase the amount of light
getting into the eye. They are sometimes used to help prevent
vision loss in very young children who need to wait for surgery to be done.
What to think about
There is currently no medicine
that will cure cataracts.
Surgery for cataracts involves removing the clouded lens of the eye
(the cataract). The lens can be replaced with an artificial lens called an
intraocular lens implant (IOL). Or, if an IOL cannot be used for any reason, it
will be left out and contact lenses or, in rare cases, eyeglasses can compensate for
its absence. Most people will get an IOL during surgery.
surgery, ask your doctor about what types of IOLs can go in your
eye. Or, if you will not be getting an IOL, ask
about the pros and cons of contact lenses or eyeglasses.
Options to help you see better after surgery
Intraocular lens (IOL). A variety of IOL
types are available. Work with your doctor to choose the best
one for you.
Contact lens. You will need to
insert, remove, and clean the lenses on a regular basis. A contact
lens may not be a good choice for young children or older adults who have a
hard time properly placing the lens on the eye.
Cataract glasses. Cataract glasses were used for
decades when there were no other options for lens replacement. Because they are
thick and heavy, they are rarely used now.
For most adults, surgery is only needed when vision
loss caused by a cataract affects your quality of life. The goals of surgery in
adults who have cataracts include:
return to work, leisure, and other daily activities.
The choices for
treating cataracts in children depend on how likely
the cataracts are to interfere with the development of normal vision. Surgery for
cataracts in children may be needed.
For adults who have cataracts in
both eyes, surgery is not normally done on both eyes at the same time. The
first eye needs to heal. Then your doctor will determine how much eyesight has
improved before surgery is done on the second eye.
There are two types of
cataract surgery. They are both done in an
outpatient center. The decision about which
one to use depends on what kind of cataract you have and how much experience
the surgeon has with each type of surgery.
Phacoemulsification (small-incision surgery). In this type of surgery, the
incisions are small, and sound waves (ultrasound) are used to break up the lens
into small pieces. This is the most common method of doing cataract
Standard extracapsular cataract extraction (ECCE). In this type of surgery,
the lens and the front portion of the lens capsule wrapped
around the lens is opened. The lens is then carefully removed in one piece.
In the past, cataracts were removed by
intracapsular surgery in which the entire lens and
lens capsule were removed. Intracapsular surgery is rarely, if ever, used
today. It is more difficult and has a higher rate of complications than
The most common problem after cataract surgery is clouding of the posterior lens capsule
(called aftercataract) within 5 years after surgery. This clouding is
usually not a serious problem. And it is easy to treat with a laser surgery
(Nd:YAG laser posterior capsulotomy) if it occurs.
What to think about
For adults, cataract surgery is
almost always elective and can be done at your convenience. The surgeon, or
someone familiar with routine surgical practices, will usually be available for
any follow-up exams and treatment.
Surgery may be advisable if you want to continue to
drive a car. If you live in a retirement home or assisted-living facility, you
may decide to use vision aids and avoid surgery.
If you do not have another eye
condition, such as glaucoma or problems with your
retina, your chances of seeing better after cataract
surgery are very good. But you may still need reading glasses or glasses for
Just because you have a cataract doesn't mean you
need to have it removed. Only you can decide whether cataracts are affecting
your vision and your life enough for you to have surgery. Learn
what to ask about cataract surgery before deciding whether to have the
Other Places To Get Help
Eye Surgery Education Council
4000 Legato Road
Fairfax , VA 22033
The Eye Surgery Education Council website can help patients and families make decisions about eye surgery. The Council was started by the American Society of Cataract and Refractive Surgery.
P.O. Box 429098
San Francisco, CA 94142-9098
EyeCare America is a public service program of the
Foundation of the American Academy of Ophthalmology. This site aims to raise awareness about
eye diseases and eye care. It has information about eye conditions, treatments, and general eye health. You can check to see if you qualify for a free eye exam.
National Eye Institute, National Institutes of
31 Center Drive MSC 2510
Bethesda, MD 20892-2510
As part of the U.S. National Institutes of Health, the National Eye
Institute provides information on eye diseases and vision research.
Publications are available to the public at no charge. The Web site includes
links to various information resources.
National Institutes of Health Senior
9000 Rockville Pike
Bethesda, MD 20892
1-800-222-2225 Aging Information Center
This website for older adults offers aging-related
health information. The website's senior-friendly features include large
print, simple navigation, and short, easy-to-read segments of information. A
visitor to this website can click special buttons to hear the text aloud, make
the text larger, or turn on higher contrast for easier viewing.
site was developed by the National Institute on Aging and the National
Library of Medicine, both part of the National Institutes of Health
(NIH). NIHSeniorHealth features up-to-date health information from NIH. Also,
the American Geriatrics Society provides independent review of some of the
material found on this website.
Prevent Blindness America
211 West Wacker Drive
Chicago, IL 60606
Prevent Blindness America assists the visually impaired
and provides consumer information on vision problems and vision aids.
Its website has information about eye health and safety for children
and adults. Many states have local affiliates.
Awasthi N, et al. (2009). Posterior capsular opacification. Archives of Ophthalmology, 127(4): 555–562.
Harper RA, Shock JP (2008). Lens. In P Riordan-Eva, JP Whitcher, eds., Vaughan and Asbury's General Ophthalmology, 17th ed., pp. 170–178. New York: McGraw-Hill.
Long V, et al. (2007). Surgical interventions for bilateral congenital cataract. Cochrane Database of Systematic Reviews (1).
Wright KW (2008). Pediatric cataracts section of Leukocoria: Cataracts, retinal tumors, and Coats disease. In Pediatric Ophthalmology for Primary Care, 3rd ed., pp. 286–300. Elk Grove Village, IL: American Academy of Pediatrics.
How this information was developed to help you make better health decisions.