what to know about the eyes

8/8/2019 What to Know About the Eyes

1/24

Parts

Eye Fun Facts

Imperfect

Eye Sights

How it Works

Function of

Each Parts

Eye Movement

THE EYES


2/24

THE EYES

Introduction:

From the moment you wake up in

the morning to the time you go to

sleep at night, your eyes are actinglike a video camera. Everything you

look at is then sent to your brain for

processing and storage much like a

video cassette. This is a verysimplified explanation, you will

discover why the sense of sight is

actually considered the most

complex of the five senses.

Parts

Eye Fun Facts

Imperfect

Eye Sights

How it Works

Function of

Each Parts

Eye Movement


3/24

THE EYES

Take a moment to locate an object

around you. Do you know how you are

able to see it? Would you believe that

what you are actually seeing are

beams of light bouncing off of the

object and into your eyes? It is hard to

believe, but it is true.

Parts

Eye Fun Facts

Imperfect

Eye Sights

How it Works

Function of

Each Parts

Eye Movement


4/24

THE EYES

The light rays enter the eye through

the cornea, which is a thick,

transparent protective layer on the

surface of your eye. Then the light

rays pass through the pupil (the dark

circle in the centre of your eye) and

into the lens.

Parts

Eye Fun Facts

Imperfect

Eye Sights

How it Works

Function of

Each Parts

Eye Movement


5/24

THE EYES

Your lens in your eyes change size all

the time. When you look at objects real

close up, the lens gets thicker. If you

look at objects far away, it gets thinner.

It does this to help you focus the

correct image on the retina.

Parts

Eye Fun Facts

Imperfect

Eye Sights

How it Works

Function of

Each Parts

Eye Movement


6/24

THE EYES

After light passes through the lens

it shines through the vitreous

humor to the back of the eyewhere it hits the retina. The retina

takes the light and changes it into

nerve impulse so the brain can

understand what the eye sees. It

sends the message to the brain

by way of the optic nerve.

Parts

Eye Fun Facts

Imperfect

Eye Sights

How it Works

Function of

Each Parts

Eye Movement


7/24

THE EYES

Function of

Each Parts


8/24

THE EYES

Cornea: The cornea is a clear white

covering over the outside of the eye.

It helps the eye focus like a lens on

a camera.Iris: The iris is the part of your eye

that has color. It gets bigger and

smaller to let in different amounts of

light.

Pupil: Black opening in the middle of

the eye. Light comes through this

opening.

Parts

Eye Fun Facts

Imperfect

Eye Sights

How it Works

Function of

Each Parts

Eye Movement


9/24

THE EYES

Aqueous humor: The aqueous

humor is clear water-like substance

that keeps your eye clean. It also

provides nutrition.Lens: The lens bends light. This

helps the eye see close up and far

away things.

Vitreous Humor: The vitreous humor

is clear water-like substance in the

back of your eye.

Parts

Eye Fun Facts

Imperfect

Eye Sights

How it Works

Function of

Each Parts

Eye Movement


10/24

THE EYES

Retina: The retina has nervecells called rods and cones that

detect light. It is in the back of

your eye.

Optic Nerve: The optic nerve

carries electrical signals fromyour retina to your brain so you

can see.

Parts

Eye Fun Facts

Imperfect

Eye Sights

How it Works

Function of

Each Parts

Eye Movement


11/24

THE EYES

Rods and Cones:

Rods and cones are special cells

that process light.

Rods and cones are extremely

small. In fact, there are about 120million rods and 7 million cones in

each eye!

Parts

Eye Fun Facts

Imperfect

Eye Sights

How it Works

Function of

Each Parts

Eye Movement


12/24

THE EYES

Continuation...

Rods help us see black and

white and shades of grey.

Cones help us see color. You

have three kinds of cones are - red,

green, and blue. These cones work

together to help us see millions of

colors.

Parts

Eye Fun Facts

Imperfect

Eye Sights

How it Works

Function of

Each Parts

Eye Movement


13/24

THE EYES

When you see

images, they turn

upside down when

they hit the retina.So your brain sees

everything in the

world upside down.

Your brain basicallyflips everything

around so it is right

side up again.

Parts

Eye Fun Facts

Imperfect

Eye Sights

How it Works

Function of

Each Parts

Eye Movement


14/24

THE EYES

There are the six small muscles that

move each eye from side to side, up

and down and on the slant. When

these muscles don't work together, itcan affect vision. One condition that

can arise when these muscles don't

work together is lazy eye, a condition

that affects about 5% of children andarises when the eye muscles don't

work together properly. This leads to

"lazy eye," in which one eye takes

over all the vision duties.

Parts

Eye Fun Facts

Imperfect

Eye Sights

How it Works

Function of

Each Parts

Eye Movement


15/24

THE EYES

A defining characteristic of these

tiny muscles is that they are

nearly always moving, even

during sleep. In fact, even when

"staring" at a fixed object, the

eyes keep moving over the

image.Although these musclesare very small, they use a lot of

energy because they are always

on the go. Eye Protection

Parts

Eye Fun Facts

Imperfect

Eye Sights

How it Works

Function of

Each Parts

Eye Movement


16/24

THE EYES

Because the eye is such an important

and complex part of our body, we have

many features which protect the eye.

The eyebrows are the strips of

hair above your eyes which prevent

sweat from running into them.

Parts

Eye Fun Facts

Imperfect

Eye Sights

How it Works

Function of

Each Parts

Eye Movement


17/24


18/24

THE EYES

The eyelids sweep dirt from the

surface of the eye. The eyelid also

protects the eye from injury.

Tears are sterile drops of clean

water which constantly bathe thefront of the eye, keeping it clean

and moist.

Parts

Eye Fun Facts

Imperfect

Eye Sights

How it Works

Function of

Each Parts

Eye Movement


19/24

THE EYES

Imperfect Eyesight:

Nearsighted and Farsighted

Not all people have perfect vision.

People who can see things up close,

but not far away are considered to be

nearsighted. This happens when the

light entering the eye focuses on a point

in front of the retina.

Parts

Eye Fun Facts

Imperfect

Eye Sights

How it Works

Function of

Each Parts

Eye Movement


20/24

THE EYES

Continuation...

On the other hand, people who can

see far away objects but not those

that are up close are farsighted.

Farsightedness occurs when thelight that enters the eye focuses on

a point behind the retina.

Parts

Eye Fun Facts

Imperfect

Eye Sights

How it Works

Function of

Each Parts

Eye Movement


21/24

THE EYES

Most people blink every 2-10

seconds.Each time you blink, you shut

your eyes for 0.3 seconds, which

means your eyes are closed at least30 minutes a day just from blinking.

If you only had one eye, everything

would appear two-dimensional. (This

does not work just by closing oneeye.)

Owls can see a mouse moving over

150 feet away with light no brighter

than a candle.

Parts

Eye Fun Facts

Imperfect

Eye Sights

How it Works

Function of

Each Parts

Eye Movement


22/24

THE EYES

The reason cat's and dog's eyes glow

at night is because of silver mirrors in

the back of their eyes called the

tapetum. This makes it easier forthem to see at night.

An ostrich has eyes that are two

inches across. Each eye weighs more

than their brain.

A chameleon's eyes can look in

opposite directions at the same time.

Parts

Eye Fun Facts

Imperfect

Eye Sights

How it Works

Function of

Each Parts

Eye Movement


23/24

THE EYES

A newborn baby sees the world

upside down because it takes

some time for the baby's brain tolearn to turn the picture right-side

up.

One in every twelve males is

color blind

Parts

Eye Fun Facts

Imperfect

Eye Sights

How it Works

Function of

Each Parts

Eye Movement


24/24

THE EYES

THANK YOU!!

what to know about the eyes

Documents