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Tears
A mixture of salt and water. Tears clean the eye of debris, prevent
the eyes from drying out and provide lubrication allowing the eyes
to constantly and comfortably move. Tears are produced in the tear
glands, flow across the eye and empty into the lacrimal duct. When
we cry, we excrete more tears than normal. This causes the lacrimal
duct to overflow requiring some of the tears to flow down our cheek.
Tears from the lacrimal duct drain into the nose, which explains
why we sniffle when we cry. The large amount of tears flowing through
our lacrimal duct flows right through our nose and out the nostrils,
dragging mucous with it. Some of the tears might flow down the back
of the nasal cavity and into the throat, giving us a salty taste
when we cry.
Why do we cry?
Crying is a natural reflex that begins
as soon as a baby is born. It's a necessary expressive act including
loud vocalizations, tears and certain facial expressions. A baby
will cry, because it needs something or because crying is its only
known form of expression. Crying alerts the mother to the baby's
needs. It causes the mother to pick the baby up and hold it, thus
keeping the baby warm, and forming an emotional bond between the
mother and infant. If the baby's crying continues it causes
people to investigate what the baby needs and to fill those needs,
whether the baby is hungry and needs to breast feed, or lacking
stimulation and needs visual interaction to aid brain development.
In this way the natural reflex of crying acts as a survival tool
to ensure that the baby has the support it needs while it's
still dependant on others to survive. In adulthood the natural reflex
of crying remains as a way to alarm others and as a powerful manner
of expression. We cry when we feel emotional or physical pain or
when we're extremely happy. When we are hurt physically, it
alerts others to come to our aid. When we are affected emotionally,
it lets others know of the consequences of their actions or once
again alerts others to come to our aid. It also gives us a way of
releasing stress, by forcing us to face the discomfort we're
feeling. In these ways crying continues to act as a survival tool.
When participating in outdoor activities that
subject your eyes to bright sunlight, wear ultraviolet protective
sunglasses. Activities involving snow and water such as fishing,
skiing, snowboarding, lifeguarding, etc. subject your retinas to
high levels of reflected ultraviolet radiation. Wearing good quality
sunglasses will protect your eyes and protect you from making a
mistake due to poor visibility and thus injuring some other part
of your body.
Important: You should
not wear sunglasses or tinted glasses on a regular basis throughout
the day. It's good to block long exposure to ultraviolet rays.
But during the rest of the day, you need light for your body to
function normally. The pineal gland, which helps regulate metabolism,
behavior, and your physiology is controlled by light. Parts of your
brain are controlled by periods of light and darkness throughout
each day to regulate your system and sleeping behavior. So don't
wear sunglasses all day. Only wear them when needed and don't
wear them at night, Silly, or you will trip and fall.
If you wear contacts. Do not leave them in your
eyes over night no matter what type they are. You can cause infection
and damage the cornea. An eye infection left untreated can eventually
cause blindness. Be careful with those finger nails when taking
out your contacts also.
Some tasks, such as working at a computer, reading
a book, building a model, or completing a detailed drawing, can
strain the eyes if done for long periods of time. During these activities
the eyes are required to focus intensely at close range. It's
like sitting in a fixed position with your head hanging over a book
for hours at a time, causing the neck and back muscles to become
strained. Like other muscles in your body, your eye muscles are
used to constant movement. If limited to a specific position, they
can also become strained. Working at a computer every day can cause
eyestrain, headaches, blurred vision, dryness, irritation, sensitivity
to light, double vision and after images. When performing these
tasks make sure to take periodic breaks, by looking up and focussing
on objects of varied distances around the room. Operating under
low levels of light can also strain the eyes.
When participating in activities that put your
eyes at risk for injury due to projectiles or flying debris, always
use safety goggles.
Wear your safety goggles in chemistry lab when
dealing with eye irritants or chemicals that may cause damage if
splashed into the eyes. In the case of emergency immediately flush
the eye with clean water.
When exposing the eyes to chlorine, such as during water polo, milk
is effective at flushing the chlorine out of the eyes.
When working with wood or metal, always wear safety goggles.
When playing racquetball, always wear safety goggles.
Aspirin, Marijuana, and other drugs such as
Tetracycline can cause damage to the eyes. So as usual always take
over-the-counter-medication as indicated in the directions. Avoid
illegal drugs. And only use prescribed drugs for the illness they
were prescribed for, and only according to the instructions given
by your doctor.
Nutrition
A well balanced diet with plenty of fresh fruits and vegetables
(especially yellow and yellow orange foods such as carrots, yams,
and cantaloupes) can keep your eyes healthy.
Fresh fruits and veggies provide the vitamins
(A, B, C, and E) and minerals (selenium and zinc) needed for your
eyes to remain healthy.
Fresh carrot juice is excellent for your eyes.
Broccoli, carrots, cauliflower, squash and sunflower
seeds are good for your eyes.
Egg yolks, fish, lamb, lima beans, meats, mushrooms,
pecans, poultry and sunflower seeds will provide zinc, which may
help reduce vision loss. (Never take over 100 mg of zinc daily.)
- The retina captures 10 images per second
throughout its working life.
- Eyes at birth are 2/3 their mature size.
- One out of every 20 people is colorblind.
- One out of every 12 men is colorblind.
- There are 6 to 7 million cones (color light
receptors) and 120 to 125 million rods (black and white receptors)
in each eye.
- Pupils are holes through which the dark
interior of the eye can be seen.
- Blinking causes the eyes to be closed for
a total of one hour each day.
- Tears enter tiny holes on the inside corner
of the eye, travel down the lachrymal duct and into the nose causing
you to sniffle when you cry, or to sniffle when cold wind causes
more lubrication of the eye.
Nervous
System
Brain
Ears
Nose
Tongue
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