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MY BODY
TEMPLE
PART 26
The
Seeing Eye
“The
hearing ear, and the seeing eye, the LORD hath made even both of
them.” Proverbs 20:12
The
eye is one of the most wonderful organs in the whole body. It lets us
know what is going on around us and to enjoy many beautiful things
that our other senses can tell us nothing about. It also allows us to
read. Let’s learn about this wonderful organ that our Creator has
given us.
Looking
at the eye, we see first a round part that rolls in different
directions. This is the eyeball. We see only the front of it, as it
fits into a hollow in the skull in a safe place where it is not likely
to get hurt. The eyeball is filled with a clear, jelly substance, so
clear that the light can shine through it as easy as through water.
If
you look closely at the eyeball you will see a small black hole just
in the center. This is a little window, called the pupil, to lets the
light into the inside. Around the pupil is a colored ring called the
iris. We say we have blue or brown or gray eyes according as the iris
is blue or brown or gray. It is a kind of curtain for the window of
the eye.
Look
closely at your pupils in a mirror while you bring a small flashlight
to shine near them then turn it off, you will see them get larger and
smaller. If you look at the light, the pupil is small; if you turn
away from the light, the pupil gets larger. This is because the
curtain closes when in a bright light and opens in the darkness. It
does this without our thinking about it, so the eye is protected
from too strong a light.
If
you look a little sideways at an eyeball, you will see that the
curtain has something in front of it as clear as glass. It is called
the cornea. In fact, this is the window to the eye. The white of the
eye is a tough, firm membrane around the eyeball that keeps it in a
round shape.
You
have seen the lens in a camera or in people’s glasses, well, there
is a lens in the eye almost like one of these lenses, only smaller.
The lens is in the eyeball just behind the pupil.
But
a person might have an eyeball with all the parts and yet not be able
to see. More is needed, there must be a nerve. The optic nerve comes
from some little nerve cells in the brain into the eyeball at the back
of the eye; there it is spread out on the inside of the black lining
of the white of the eye. This membrane is called the retina.
Let’s
notice some other parts about the eye. First there are the eyelids.
They are little folds of skin, which we can shut to cover the eyeball
and keep out the light when we want to sleep or to keep from getting
dust or smoke into the eye. The eyelids are fringed with hairs placed
along the edge of the lids to help keep the dust out when the eyes are
open. The eyelids also help to keep the eye moist. This is why we
blink from time to time.
The
row of hairs above the eye is called the eyebrow. Like the eyelids,
the eyebrows catch some things that might fall into the eye, and they
also help to keep sweat out of the eyes.
Do
you know where tears come from? There is a little gland snugly placed
away in the socket of the eye just above the eyeball, which makes
tears in the same way that the salivary glands make saliva. It is
called the tear gland. The gland usually makes just enough tears to
keep the eye moist. There are times when it makes more, as when
something gets into the eye, or when we suffer pain or feel unhappy.
Then the tears flow into a little tube, the tear duct, which runs down
into the nose from the inner corner of the eye. When the tears are
formed so fast that they cannot all get away through this tube, they
run out and flow down the cheek.
Little
muscles that are fastened to the eyeball let us turn the eye in almost
every direction.
How
does the eye see? It is hard to understand, but we can learn something
about it. Let's do an experiment. Take a magnifying glass, hold it
before a window and place a piece of white paper behind it on the side
away from the window. If you move the glass back and forth till an
image is focused on the paper, you will be able to see a picture on
the paper of whatever is outside the window. The picture made by the
lens looks exactly like the view out-of-doors, except that it is
upside down. This is one of the interesting things that a lens does.
The
lens of the eye acts like the glass lens. It makes a picture upon the
retina of everything we see. The nerves in the retina transfer the
picture spread out at the back of the eyeball to the brain. This is
how we see. There is a mystery here, because just like with the glass
lens, the picture on the retina is up-side-down, but we see right way
up!
Did
you ever look through binoculars or a telescope? You must focus on
the object you are looking at by making the telescope a little longer
or shorter. The eye also has to be changed a little when we look from
near to distant objects. Look out of the window at a tree a long way
off. Now place a pencil between the eyes and the tree. You can
scarcely see the pencil while you look closely at the tree, and if you
look at the pencil you cannot see the tree clearly.
There
is a little muscle in the eye that makes the change needed to see
close objects as well as those farther away. When people grow old the
little muscles cannot do this so well, so old people sometimes have to
put on glasses to see objects near by and read.
To
keep the eyes healthy we need to eat a good diet. A high fat diet has
been proven to cause eye damage. The tiny capillaries that bring the
blood to the retina can become plugged, causing retina injury. Vitamin
A found in orange and yellow fruits and vegetables is good for your
eyes.
Always
be careful to protect the eyes from things that might get in and hurt
them and from sharp objects. When working with sanders and saws or
around any flying debris, it is a good idea to wear safety goggles.
Sight is a precious gift God has given us and should be protected.
=^..^=
 
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