Warning
Signs of Eye Trouble
Blurry vision, spots, glare
at night -- these are common eye complaints that can be harmless annoyances or
an early sign of disease. In the slides ahead, we explore several eye problems
and offer two quick eye tests. You'll see the world through eyes that have
floaters, cataracts, myopia, and glaucoma. Be sure to see an eye doctor
promptly for any concerns.
Nearsightedness
(Myopia)
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- Family history (one or both parents)
- Lots of prolonged, close-up reading
- Trouble with driving, sports, or seeing a blackboard or the TV may ensue. Symptoms include blurred vision, squinting, and fatigue. Myopia can be treated with glasses, contacts, or surgery in some cases.
Farsightedness (Hyperopia)
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Presbyopia
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Nearsightedness:
What Happens
Typically, an eyeball that's
too long causes myopia. But an abnormally shaped cornea or lens can also be to
blame. Light rays focus just in front of the retina, instead of directly on it.
This sensitive membrane lines the back of the eye (seen in yellow) and sends
signals to the brain through the optic nerve. Nearsightedness often develops in
school-age children and teens, which need to change glasses or contacts
frequently as they grow. It usually stabilizes by the early 20s.
Farsightedness:
What Happens
In hyperopia, the cause is
often an eyeball that is too short. Light rays focus behind the retina, causing
close objects to be blurry. In severe cases of hyperopia, especially after the
age of 40, distance vision can be blurred as well. An abnormal shape in the
cornea or lens can also lead to farsightedness. Children with significant
hyperopia are more likely to have crossed eyes (strabismus) or lazy eye
(amblyopia) and may have difficulty reading. That’s one of the reasons eye doctors
recommend vision exams for young children.
Astigmatism
Your vision may be out of
focus at any distance with an astigmatism in one or both eyes. It occurs when
the cornea, the clear “window” that covers the front of the eye, is misshapen.
Light rays can be scattered in different points on the retina, rather than
focusing on a single point. Glasses or contact lenses correct the problem, and
surgery may be another option. Along with blurred vision, symptoms may include
headaches, fatigue, and eye strain.
Color Blindness Test
Which number do you see in
the far left? If it's "3," you probably have normal color vision. If
it's a "5," you may be colorblind. This view is simulated in
the center panel and represents a mild color vision deficiency. About 10%
of men are born colorblind, but few women. Complete color blindness (very rare)
is simulated at right. No number is visible. Tinted glasses may help the
colorblind see better.
Refractive
Eye Surgery
Do you dream of seeing
clearly without glasses? Surgery to reshape the cornea can correct
nearsightedness, farsightedness, or astigmatism with a success rate of better
than 90%. People with severe dry eye, thin or abnormally shaped corneas, or
severe vision problems may not be good candidates. Possible side effects
include glare or sensitivity to light.
Glaucoma:
View
You can't feel it, but
deterioration of the optic nerve oftentimes with elevated eye pressure can
silently steal your sight, a condition called glaucoma. There may be no
symptoms until central vision is lost (following gradual loss of peripheral
vision), so regular eye exams are critical to find it early. Those at higher
risk include:
- African-Americans over 40
- Anyone over 60, especially Mexican-Americans
- People with a family history
Fortunately, glaucoma can be
treated with medications or surgery. Regular eye exams every 1-2 years,
especially after age 40, can catch it early.
Glaucoma:
What Happens
In the most common form of
glaucoma, increased eye pressure leads to optic nerve damage and loss of
vision. The eye is filled with circulating fluid that nourishes its internal
structures. Sometimes the balance between fluid creation and exit is abnormal.
The buildup of fluid increases pressure and damages the optic nerve at the back
-- the bundle of 1 million nerve fibers that carry information to the brain.
Without treatment, glaucoma can cause total blindness.
The bright yellow circle
shows an optic nerve head that is damaged by glaucoma. The dark central area is
the macula, responsible for finely-detailed central vision.
Macular
Degeneration: View
Age-related macular
degeneration (AMD) damages, then destroys, the eye's finely-detailed central
vision, making it difficult to read or drive. Symptoms can include a central
blurry spot or straight lines that appear wavy. Finding and treating AMD
promptly can help slow vision loss. Being over 60, smoking, high blood
pressure, obesity, and a family history of AMD increase your risk.
Macular
Degeneration: What Happens
In AMD, the central part of
the retina, called the macula, deteriorates. In the dry form, doctors often see
yellow deposits called drusen in the macula. As dry AMD progresses, the macular
tissue deteriorates, gradually shutting down the delivery of images to the
brain.
In the wet form, abnormal blood vessels grow.
They leak blood and fluid (seen here), causing scarring and further damage to
the macula. Both types lead to a central blind spot.
Macular
Degeneration: Test
Cover one eye and stare at
the center dot in this Amsler Grid, from a distance of 12 to 15 inches. (You
can wear your reading glasses.) Do you see wavy, broken, or blurry lines? Are
any areas distorted or missing? Repeat the procedure for your other eye. While
no self-test can substitute for an eye exam, this grid is used to help detect
early symptoms of AMD.
Macular
Degeneration:Signs
As seen here, the Amsler
Grid can look quite distorted to someone with significant macular degeneration
and may include a central dark spot. Straight lines that appear wavy are also
cause for concern, as they can be an early symptom of "wet" AMD, the
more serious and fast-moving type of macular degeneration. Your eye care
professional will want to evaluate you right away, starting with a thorough
dilated eye exam.
Diabetic
Retinopathy: View
Type 1 and type 2 diabetes
can cause partial vision loss (seen here) and lead to blindness. The damage
involves tiny blood vessels in the retina and can often be treated, but don't
wait for symptoms. By the time they occur -- blurry vision, spots, shadows, or
pain -- the disease may be severe. People with known diabetes need annual eye
exams, sometimes even more often if diabetic eye changes have begun. The best
prevention is keeping your blood sugar in check.
Diabetic
Retinopathy: What Happens
When high blood sugar levels
go unchecked, it can damage the tiny blood vessels that support the retina.
These blood vessels can swell, break, and leak fluid. In some cases,
dozens of new, abnormal blood vessels grow, a condition called proliferative
retinopathy. The abnormal vessels are very fragile and break open easily. These
processes gradually damage the retina, causing blurred vision, blind spots, or
blindness.
Cataracts: View
Age is not kind to our eyes.
By the time we're 80 years old, more than half of us will have had a cataract,
or clouding of the lens. Vision gradually gets foggy and makes it hard to read,
drive, and see at night. Diabetes, smoking, or prolonged sunlight
exposure may increase the risk. Surgery that replaces the clouded lens with an
artificial lens is highly effective.
Cataracts:
What Happens
In good health, the lens focuses
light into a sharp, clear image on the retina, which captures the image like
film in a camera. As we age, protein builds up in the lens, clouding it, and
sending scattered rays of light to the retina, instead of one sharp clear
image. The result can be blurred vision, changes in color vision, and glare,
especially at night. Very advanced cataracts are visible to the naked eye --
the muddy-colored circle at the center of this picture.
Retinitis
Pigmentosa
RP is an inherited disorder
that often begins with night vision problems, followed by a gradual loss of
side vision, developing into tunnel vision, and finally, in some cases,
blindness. One in 4,000 American have RP. A promising study showed that
high-dose vitamin A supplements can reduce vision loss. However, you should
consult a health care expert before taking supplements because too much vitamin
A can be toxic.
Retinitis
Pigmentosa : What Happens
The light-sensitive tissue
of the retina slowly deteriorates over many years in people with RP. As this
tissue dies, it stops sending signals to the brain, and some vision is lost.
Eye exams show abnormal dark spots (pigments) sprinkled around the
retina. Early cataracts can also occur, as well as a swelling of the retina
called macular edema (the central orange mass seen here).
Floaters
and Specks
Blurry spots or specks in
your vision that move may be floaters -- debris in the eye's vitreous gel. They
don't block vision and are more easily seen in bright light. Floaters are
common and usually harmless. But if they appear or increase suddenly, or are
accompanied by light flashes, you should see a doctor. Vision abnormalities
that tend to be more serious include persistent white or black spots and a
sudden shadow or loss of peripheral vision. These require immediate evaluation.
Amblyopia (Lazy Eye)
During childhood, when
vision is reduced in one eye, the brain sometimes favors the other eye. This
condition, called amblyopia, may stem from a misalignment of the eyes
(strabismus or crossed eyes) or poorer vision in one eye. A patch or drops that
blur the vision in the "good" eye can prod the brain to use the other
eye. If untreated during childhood, vision loss from amblyopia can be
permanent.
Eye
Care: Tears and Dry Eye
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Eye
Care: Pinkeye
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Eye
Care: Stye
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Eye
Care: Regular Exams
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Eye
Protection: Sun
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Eye
Protection: Everyday Hazards
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Foods
for Eye Health
Carrots really are
good for your eyes. So are spinach, nuts, oranges, beef, fish, whole grains,
and many other foods in a healthy diet. Look for foods with antioxidants such
as omega-3 fatty acids; vitamins C, E, and beta-carotene; as well as zinc,
lutein, and zeaxanthin. Research suggests those nutrients may reduce the risk
of age-related macular degeneration.
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