Eyes are very important organ of our body. Although every
part is equally important, eyes are very precious organs. It would be quite
difficult to enjoy and understand the world without the eyes.
Think, what
would be the world like without your eyes!
The eyes help
us to know beauty, size and shape, brightness and darkness, height and depth,
distances, colours and various other things.
Structure of eye
When we look
from outside, we can see following parts in our eyes:
Each eye consists of an eyeball. It moves
with the help of muscles called ocular muscles. The eyes are externally
protected with the help of eyelids. The eyelids keep the eyes moist and clear.
They also protect the eyes from harmful foreign things. The eyelashes are the
hairs that grow from the margin of eyelids. The eyelashes help to trap dust
particles and tiny insects and prevent them from entering into the eye. The
borders of short hairs above the eyelids are called eyebrows. They form the
distinct border between forehead and eyes.
When we
observe from outside, the eyeball appears white ball with a dark round in the
middle. The internal eye is made of three layers- sclera, iris and retina. The
outermost white and strong part of eyeball is called sclera. The front portion
of sclera is transparent and is known as cornea. The black or brown structure
just under the cornea is called iris. The iris gives the colour to the eyes.
The eyes people can be black, grey, brown or blue due to the colour of iris.
There is a small gap between the two strands of iris in the front part of eyes.
This gap is called pupil. The light enters our eyes through the pupil.
The
innermost layer of eyes is called retina. It acts like the screen of camera.
The retina forms the inverted (upside down) image of an object what we see
around us. The retina has a number of light sensitive cells and optic nerve.
The optic nerves carry the inverted picture formed in retina to the brain. The
brain percepts the picture and makes it erect. Then we see the object. It is a
very rapid process.
Defects of eye
The eyes are very delicate
sense organs. They can be harmed or damaged easily. Very bright or dim light,
knitting works, watching TV from near distance, improper diet, improper angle
of looking while reading books, etc can harm our eyes. Our eyes can also be
infected by the germs. Sometimes, the eyes gradually become unable to see the
objects clearly due to some internal reasons. The inability of the eyes to see
the objects clearly is called defect of eyes. Short-sightedness,
long-sightedness, cataract, glaucoma, night
blindness and colour blindness are some defect of eyes.
A person
who is suffering from short-sightedness, can see the near objects only but
cannot see the distant objects. Similarly, a person who is suffering from
long-sightedness, can see the far objects only and cannot see at night.
Cataract is common in old people. In cataract, there is opacity in eye lens and
gradual loss of vision occurs.
Care of eyes
1.
Avoid reading by lying on the bed.
2.
Do not read in dim or very bright light. Do not
place the book near or too far from eyes while reading. The reading distance
should always be maintained between 25 to 35cm.
3.
Do not rub the eyes when dust particle enter into
them. Let the dust be washed away by tears or dip the open eyes into the tub of
clean water. The water washes away the dust or dirt.
4.
Protect your eyes from foreign bodies like dust
particles, coal pieces, insect and small stones. These things cause a lot of
damage to our eyes if they enter into them.
5.
Never look at the glare of the sun. it can damage
your eyes permanently.
6.
Maintain at least 6 feet distance between the TV
screen and your eyes while watching the TV.
7.
Eat fruit and vegetables that provide you vitamin
A. Meat, fish, liver, milk etc also provide you vitamin A. The vitamin A saves
you from night blindness.
8.
If you have defects of eyes, headache etc, visit
the ophthalmologist (eye doctor) for treatment. You may need glasses to wear.
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