3-5-2 The Eye

Find the cornea on the picture below.   The cornea is a transparent or see-through covering on the outside of the eye.  Light passes through the cornea, and then through the pupil, an opening in the eye.  Find the lens that sits behind the pupil.  The lens puts the light in focus.  The lens in your eye acts just like the lens in a camera.  The lens of your eye focuses a picture on a special surface at the back of the eye.  The image however is upside-down.  This special surface at the back of the eye is called the retina.  Find the retina on the picture below.

The retina sends images to the optic nerve, which then sends them to the brain.  This is where the image is flipped right side up.  This happens very quickly; so quickly you don't even notice it.

The pupil of the eye gets bigger and smaller automatically.  The size of the pupil adjusts so the eye will not be injured.  If the light is too dim, the pupil opens up to let more light hit the retina.  If the light is too bright, the pupil closes to let less light in.

The part of the eye that adjusts the size of the pupil is called the iris.  The iris is the part of your eye that is colored brown, blue, or green.

People who wear glasses do so because their eyes don't work properly.  Some people are nearsighted.  This means that they can see things close up, but have trouble seeing things far away.  People who are farsighted can see things far away, but have trouble seeing things that are nearby.

It is important to have your eyes and vision checked by a doctor.  If a problem is found, you may need glasses.  The lenses of glasses are shaped to help your eyes work properly.

Directions: Answer the questions below about the eye and how it works.

The transparent or see-through covering on the outside of the eye is called the .

The opening in the eye is called the .  It can get bigger or smaller.

What sits directly behind the pupil of the eye?

cornea
lens
optic nerve

The surface at the back of the eye is called the .

How does the image at the back of the eye appear?

right side up
up-side down

The optic nerve sends messages to the .

The colored part of the eye that adjusts the size of the pupil is called the .

If you can see things close up, but have trouble seeing things far away you are

farsighted
nearsighted

If you can see things far away, but have trouble seeing things close up, you are

farsighted
nearsighted