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Hearing
Vision |
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Vision |
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Vision-
The special sense by which
the qualities of an object (as color,
luminosity, shape, and size) constituting its
appearance are perceived through a process in
which light rays entering the eye are
transformed by the retina into electrical
signals that are transmitted to the brain via
the optic nerve. |
| Vision
changes and problems can be caused by many
different conditions: |
Presbyopia
-- difficulty focusing on objects that are
close. Common in the elderly.
Cataracts --
cloudiness over the eye's lens, causing poor
nighttime vision, halos around lights, and
sensitivity to glare. Daytime vision is
eventually affected. Common in the elderly.
Glaucoma --
increased pressure in the eye, causing poor
night vision, blind spots, and loss of vision to
either side. A major cause of blindness.
Glaucoma can happen gradually or suddenly -- if
sudden, it's a medical emergency.
Diabetic retinopathy
-- this complication of diabetes can lead to
bleeding into the retina. Another common cause
of blindness.
Macular degeneration
-- loss of central vision, blurred vision
(especially while reading), distorted vision
(like seeing wavy lines), and colors appearing
faded. The most common cause of blindness in
people over age 60.
Eye infection, inflammation, or injury.
Floaters -- tiny
particles drifting across the eye. Although
often brief and harmless, they may be a sign of
retinal detachment.
Retinal detachment
-- symptoms include floaters, flashes of light
across your visual field, or a sensation of a
shade or curtain hanging on one side of your
visual field.
Optic neuritis --
inflammation of the optic nerve from infection
or multiple sclerosis. You may have pain when
you move your eye or touch it through the
eyelid.
Stroke or TIA.
Brain tumor.
Bleeding into the eye.
Temporal arteritis
-- inflammation of an artery in the brain that
supplies blood to the optic nerve.
Migraine headaches
-- spots of light, halos, or zigzag patterns are
common symptoms prior to the start of the
headache. An ophthalmic migraine is when you
have only visual symptoms without a headache. |
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| Sources: U.S.
National Library of Medicine,
National Institutes of Health | Department of Health & Human Services
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These
important steps can prevent eye and vision problems:
Wear sunglasses to protect your eyes.
Don't smoke.
Limit how much alcohol you drink.
Keep your blood pressure and cholesterol under
control.
Keep your blood sugars under control if you have
diabetes.
Eat foods rich in antioxidants, like green leafy
vegetables |
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Amblyopia.net |
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