vision deficiency means that your ability to distinguish some
colors and shades is less than normal. It occurs when the color-sensitive
cone cells in your eyes do not properly pick up or send the proper color
signals to your brain. About eight percent of men and one percent of
women are color deficient.
Red-green deficiency is by far the most common form and it results in
the inability to distinguish certain shades of red and green. Those
with a less common type have difficulty distinguishing blue and yellow.
In very rare cases, color deficiency exists to an extent that no colors
can be detected, only shades of black, white and grey.
Since many learning materials are color-coded, it is important to diagnose
color vision deficiency early in life. This is why the American Optometric
Association recommends a comprehensive optometric examination before
a child begins school.
Color vision deficiency is usually inherited and cannot be cured, but
those affected can often be taught to adapt to the inability to distinguish
colors. In some cases, a special red tinted contact lens is used in
one eye to aid persons with certain color deficiencies.
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is an eye disease in which the internal pressure in your eyes increases
enough to damage the nerve fibers in your optic nerve and cause vision
loss. The increase in pressure happens when the passages that normally
allow fluid in your eyes to drain become clogged or blocked. The reasons
that the passages become blocked are not known.
Noticeable symptoms of
glaucoma may be a gradual loss of side vision (above) or blurred vision
Glaucoma is one of the leading causes of blindness in the U.S. It most
often occurs in people over age 40. People with a family history of
glaucoma, African Americans, and those who are very nearsighted or diabetic
are at a higher risk of developing the disease.
The most common type of glaucoma develops gradually and painlessly,
without symptoms. A rarer type occurs rapidly and its symptoms may include
blurred vision, loss of side vision, seeing colored rings around lights
and pain or redness in the eyes.
Glaucoma cannot be prevented, but if diagnosed and treated early, it
can be controlled. Vision lost to glaucoma cannot be restored. That
is why the American Optometric Association recommends annual eye examinations
for people at risk for glaucoma (your doctor may, depending on your
condition, recommend more frequent examinations). A comprehensive optometric
examination will include a tonometry test to measure the pressure in
your eyes; an examination of the inside of your eyes and optic nerves;
and a visual field test to check for changes in central and side vision.
The treatment for glaucoma includes prescription eye drops and medicines
to lower the pressure in your eyes. In some cases, laser treatment or
surgery may be effective in reducing pressure.
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is an inflammation of the conjunctiva, the thin, transparent layer that
lines the inner eyelid and covers the white part of the eye.
The three main types of conjunctivitis are infectious, allergic and
chemical. The infectious type, commonly called "pink eye"
is caused by a contagious virus or bacteria. Your body's allergies to
pollen, cosmetics, animals or fabrics often bring on allergic conjunctivitis.
And, irritants like air pollution, noxious fumes and chlorine in swimming
pools may produce the chemical form.
Common symptoms of conjunctivitis are red watery eyes, inflamed inner
eyelids, blurred vision, a scratchy feeling in the eyes and, sometimes,
a puslike or watery discharge. Conjunctivitis can sometimes develop
into something that can harm vision so you should see your optometrist
promptly for diagnosis and treatment.
A good way to treat allergic or chemical conjunctivitis is to avoid
the cause. If that does not work, prescription or over-the-counter eye
drops may relieve discomfort. Infectious conjunctivitis, caused by bacteria,
can be treated with antibiotic eye drops. Other forms, caused by viruses,
cannot be treated with antibiotics. They must be fought off by your
body's immune system.
To control the spread of infectious conjunctivitis, you should keep
your hands away from your eyes, thoroughly wash your hands before applying
eye medications and do not share towels, washcloths, cosmetics or eye
drops with others.
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is the leading cause of blindness in America. It results from changes
to the macula, a portion of the retina that is responsible for clear,
sharp vision and is located at the back of the eye.
As macular degeneration
advances, a distorted, dark, or empty area often appears in the center
Most people with macular degeneration have the dry form, for which there
is no known treatment. The less common wet form may respond to laser
procedures, if diagnosed and treated early.
Some common symptoms are a gradual loss of ability to see objects clearly,
distorted vision, a gradual loss of color vision and a dark or empty
area appearing in the center of vision.
If you experience any of these, contact your doctor of optometry immediately
for a comprehensive examination.
Central vision that is lost to macular degeneration cannot be restored.
However, low vision devices such as telescopic and microscopic lenses
can be prescribed to make the most out of remaining vision.
Recent research indicates certain vitamins and minerals may help prevent
or slow the progression of macular degeneration. Ask your doctor of
optometry about these. After age 60, an annual, comprehensive eye examination
is an important to maintain eye health.
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is a clouding of all or part of the normally clear lens within your
eye, which results in blurred or distorted vision. Cataracts are most
often found in persons over age 55, but they are also occasionally found
in younger people.
No one knows exactly what causes cataracts, but it is known that a chemical
change occurs within your eye to cause the lens to become cloudy. This
may be due to advancing age, heredity or an injury or disease. Excessive
exposure to ultraviolet radiation in sunlight, cigarette smoking or
the use of certain medications are also risk factors for the development
Although cataracts develop without pain or discomfort, there are some
indications that a cataract may be forming. These include blurred or
hazy vision, the appearance of spots in front of the eyes, increased
sensitivity to glare or the feeling of having a film over the eyes.
A temporary improvement in near vision may also indicate formation of
Currently, there is no proven method to prevent cataracts from forming.
During a comprehensive eye examination, your optometrist can diagnose
a cataract and monitor its development and prescribe changes in eyeglasses
or contact lenses to maintain good vision.
If your cataract develops to the point that it affects your daily activities,
your optometrist can refer you to an eye surgeon who may recommend surgery.
During the surgery, the eye's natural lens is removed and usually replaced
with a plastic artificial lens. After surgery, you can return to your
optometrist for continuing care.
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The tears your eyes produce
are necessary for overall eye health and clear vision. Dry
eye means that your eyes do not produce enough tears or that
you produce tears which do not have the proper chemical composition.
Often, dry eye is part of the natural aging process. It can also be
caused by blinking or eyelid problems, medications like antihistamines,
oral contraceptives and antidepressants, a dry climate, wind and dust,
general health problems like arthritis or Sjogren's syndrome and chemical
or thermal burns to your eyes.
If you have dry eye,
your symptoms may include irritated, scratchy, dry, uncomfortable or
red eyes, a burning sensation or feeling of something foreign in your
eyes and blurred vision. Excessive dry eyes may damage eye tissue, scar
your cornea (the front covering of your eyes) and impair vision and
make contact lens wear difficult.
If you have symptoms of dry eye, see your optometrist for a comprehensive
examination. Dry eye cannot be cured, but your optometrist can prescribe
treatment so your eyes remain healthy and your vision is unaffected.
Some treatments that your optometrist might prescribe include blinking
more frequently, increasing humidity at home or work, using artificial
tears and using a moisturizing ointment, especially at bedtime. In some
cases, small plugs are inserted in the corner of the eyes to slow tear
drainage. Sometimes, surgical closure of the drainage ducts may be recommended.
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Diabetes is a disease that interferes
with the body's ability to use and store sugar and can cause many health
problems. One, called diabetic retinopathy, can
weaken and cause changes in the small blood vessels that nourish your
eye's retina, the delicate, light sensitive lining of the back of the
eye. These blood vessels may begin to leak, swell or develop brush-like
Blurred central or side
vision (above, blurred side vision) or a blind spot in central vision
(below) may indicate diabetic retinopathy.
The early stages of diabetic retinopathy
may cause blurred vision, or they may produce no visual symptoms at
all. As the disease progresses, you may notice a cloudiness of vision,
blind spots or floaters.
If left untreated, diabetic retinopathy can cause blindness, which is
one reason why it is important to have your eyes examined regularly
by your doctor of optometry. This is especially true if you are a diabetic
or if you have a family history of diabetes.
To detect diabetic retinopathy, your optometrist can look inside your
eyes with an instrument called an ophthalmoscope that lights and magnifies
the blood vessels in your eyes. If you have diabetic retinopathy, laser
and other surgical treatments can be used to reduce its progression
and decrease the risk of vision loss. Early treatment is important because
once damage has occurred, the effects are usually permanent.
If you are a diabetic, you can help prevent diabetic retinopathy by
taking your prescribed medication as instructed, sticking to your diet,
exercising regularly, controlling high blood pressure and avoiding alcohol
November is National Diabetes Month. Members of the American Optometric
Association are joining with members of other health care organizations
in an effort to prevent blindness in Americans with diabetes. If you
or a member of your family has not received a dilated eye examination
in the past year, you should contact your optometrist for an appointment.
If you do not have an optometrist, call 1-800-262-3947 for the names
of doctors in your area.
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is a vision disorder that occurs when the normally round cornea
(the front part of the eye) becomes thin and irregular (cone) shaped.
This abnormal shape prevents the light entering the eye from being focused
correctly on the retina and causes distortion of vision.
In its earliest stages,
keratoconus causes slight blurring and distortion of vision and increased
sensitivity to glare and light. These symptoms usually appear in the
late teens or late twenties. Keratoconus may progress for 10-20 years
and then slow in its progression. Each eye may be affected differently.
As keratoconus progresses, the cornea bulges more and vision may become
more distorted. In a small number of cases, the cornea will swell and
cause a sudden and significant decrease in vision. The swelling occurs
when the strain of the cornea's protruding cone-like shape causes a
tiny crack to develop. The swelling may last for weeks or months as
the crack heals and is gradually replaced by scar tissue. If this sudden
swelling does occur, your doctor can prescribe eyedrops for temporary
relief, but there are no medicines that can prevent the disorder from
Eyeglasses or soft contact lenses may be used to correct the mild nearsightedness
and astigmatism that is caused by the early stages for keratoconus.
As the disorder progresses and cornea continues to thin and change shape,
rigid gas permeable contact lenses can be prescribed to correct vision
adequately. In most cases, this is adequate. The contact lenses must
be carefully fitted, and frequent checkups and lens changes may be needed
to achieve and maintain good vision.
In a few cases, a corneal transplant is necessary. However, even after
a corneal transplant, eyeglasses or contact lenses are often still needed
to correct vision.
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is a chronic or long term inflammation of the eyelids and eyelashes.
It affects people of all ages. Among the most common causes of blepharitis
are poor eyelid hygiene; excessive oil produced by the glands in the
eyelid; a bacterial infection (often staphylococcal); or an allergic
Blepharitis is a chronic
inflammation that affects the eyelids (1) and the eyelash hair follicles
(2). Careful eyelid hygiene can do much to control blepharitis.
is often associated with dandruff of the scalp or skin conditions like
acne. It can appear as greasy flakes or scales around the base of the
eyelashes and a mild redness of the eyelid. It may also result in a
roughness of the normally smooth tissue that lines the inside of the
Ulcerative blepharitis is less common, but more serious. It is characterized
by matted, hard crusts around the eyelashes, which when removed, leave
small sores that ooze or bleed. There may also be a loss of eyelashes,
distortion of the front edges of the eyelids and chronic tearing. In
severe cases, the cornea, the transparent front covering of the eyeball,
may also become inflamed.
In many cases, good eyelid hygiene and a regular cleaning routine may
control blepharitis. This includes frequent scalp and face washing;
warm soaks of the eyelids; and eyelid scrubs. In cases where bacterial
infection is a cause, eyelid hygiene may be combined with various antibiotics
and other medications. Eyelid hygiene is especially important upon awakening
because debris can build up during sleep.
If you experience symptoms of blepharitis, your doctor of optometry
can determine the cause and recommend the right combination of treatments
specifically for you.
Directions For A Warm Soak Of The Eyelids
1. Wash your hands thoroughly.
2. Moisten a clean washcloth with warm water.
3. Close eyes and place washcloth on eyelids for about 5 minutes.
4. Repeat several times daily.
Directions For An Eyelid
1. Wash your hands thoroughly.
2. Mix warm water and a small amount of shampoo that does not irritate
the eye (baby shampoo) or use a commercially prepared lid scrub solution
recommended by your optometrist.
3. Close one eye and using a clean wash cloth (a different one for each
eye), rub the solution back and forth across the eyelashes and the edge
of the eyelid.
4. Rinse with clear, cool water.
5. Repeat with the other eye.