Is a Cataract?
A cataract is a dense, cloudy area that forms in the lens of the
eye. A cataract begins when proteins in the eye form clumps that prevent the
lens from sending clear images to the retina. The retina works by converting
the light that comes through the lens into signals. It sends the signals to the
optic nerve, which carries them to the brain.
It develops slowly and eventually interferes with your vision.
You might end up with cataracts in both eyes, but they usually don’t form at
the same time. Cataracts are common in older people. Over half of people in the
United States have cataracts or have undergone cataract surgery by the time
they’re 80 years old, according to the National Eye Institute.
Common symptoms of cataracts include:
- blurry vision
- trouble seeing at night
- seeing colors as faded
- increased sensitivity to glare
- halos surrounding lights
- double vision in the affected eye
- a need for frequent changes in prescription
There are several underlying causes of cataracts. These include:
- an overproduction of oxidants, which are oxygen
molecules that have been chemically altered due to normal daily life
- ultraviolet radiation
- the long-term use of steroids and other
- certain diseases, such as diabetes
- radiation therapy
There are different types of cataracts. They’re classified based
on where and how they develop in your eye.
- Nuclear cataracts form in the middle of the lens
and cause the nucleus, or the center, to become yellow or brown.
- Cortical cataracts are wedge-shaped and form
around the edges of the nucleus.
- Posterior capsular cataracts form faster than
the other two types and affect the back of the lens.
- Congenital cataracts, which are present at birth
or form during a baby’s first year, are less common than age-related cataracts.
- Secondary cataracts are caused by disease or
medications. Diseases that are linked with the development of cataracts include
glaucoma and diabetes. The use of the steroid prednisone and other medications
can sometimes lead to cataracts.
- Traumatic cataracts develop after an injury to
the eye, but it can take several years for this to happen.
- Radiation cataracts can form after a person undergoes
radiation treatment for cancer.
Factors of Cataracts
Risk factors associated with cataracts include:
- older age
- heavy alcohol use
- high blood pressure
- previous eye injuries
- a family history of cataracts
- too much sun exposure
- exposure to radiation from X-rays and cancer
Your doctor will perform a comprehensive eye exam to check for
cataracts and to assess your vision. This will include an eye chart test to
check your vision at different distances and tonometry to measure your eye
The most common tonometry test uses a painless puff of air to
flatten your cornea and test your eye pressure. Your doctor will also put drops
in your eyes to make your pupils bigger. This makes it easier to check the
optic nerve and retina at the back of your eye for damage.
Other tests your doctor might perform include checking your
sensitivity to glare and your perception of colors.
If you’re unable or uninterested in surgery, your doctor may be
able to help you manage your symptoms. They may suggest stronger eyeglasses, magnifying
lenses, or sunglasses with an anti-glare coating.
Surgery is recommended when cataracts prevent you from going
about your daily activities, such as reading or driving. It’s also performed
when cataracts interfere with the treatment of other eye problems.
One surgical method, known as phacoemulsification, involves the
use of ultrasound waves to break the lens apart and remove the pieces.
Extracapsular surgery involves removing the cloudy part of the
lens through a long incision in the cornea. After surgery, an artificial
intraocular lens is placed where the natural lens was.
Surgery to remove a cataract is generally very safe and has a
high success rate. Most people can go home the same day as their surgery.
of a Cataract
Cataracts can interfere with daily activities and lead to
blindness when left untreated. Although some stop growing, they don’t get
smaller on their own. The surgical removal of cataracts is a very common
procedure and is highly effective roughly 90 percent of the
time, according to the National Eye Institute.
To reduce your risk of developing cataracts:
- protect your eyes from UVB rays by wearing
- have regular eye exams
- stop smoking
- eat fruits and vegetables that contain
- maintain a healthy weight
- keep diabetes and other medical conditions in