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To the Brain!
Think of
the optic nerve as the great messenger in the back of your eye.
The rods and cones of the retina change the colors and shapes you see into
millions of nerve messages. Then, the optic nerve carries those messages from
the eye to the brain! The optic nerve serves as a
high-speed telephone line connecting the eye to the brain. When you see an
image, your eye "telephones" your brain with a report on what you are seeing so
the brain can translate that report into "cat," "apple," or "bicycle," or
whatever the case may be.
Have No Fear, You Have Tears
For crying out loud, the eye has its own special bathing system - tears!
Above the outer corner of each eye are the lacrimal (say:
lah-kruh-mul) glands, which make tears. Every
time you blink your eye, a tiny bit of tear fluid comes out of your upper
eyelid. It helps wash away germs (tiny living creatures that
live in our bodies and can only be seen using a microscope), dust, or other
particles that don't belong in your eye. It also keeps your eye from drying out.
Then the fluid drains out of your eye by going into the lacrimal
duct (this is also called the tear duct). You can see the opening of
your tear duct if you very gently pull down the inside corner of your eye. When
you see a tiny little hole, you've found the tear duct.
Your eyes will make more tear fluid than normal to
protect themselves. This may have happened to you if you've been poked in the
eye, if you've been in a dusty or smoking area, or if you've been near someone
who's cutting onions.
And how about the last time you felt sad, scared,
or upset? Your eyes got a message from your brain to make you cry, and the
lacrimal glands made many, many tears.
Your eyes do some great things for you, so take
these steps to protect them:
- Wear goggles in classes where debris or
chemicals could go flying, such as wood shop, metal shop, science lab, or art.
- Wear eye protection when playing racquetball,
hockey, skiing, or other sports that could injure your eyes.
- Wear sunglasses. Too much light can damage your
eyes and cause vision problems, such as cataracts, later in
life. A cataract is a cloudy area that develops on the cornea, preventing
light from reaching the retina and making it difficult to see.
The eyes you've got will be yours forever - treat
them right and they'll never be out of sight!
Reviewed by: Wayne Ho,
MD
Date reviewed: September
2003
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