Chapter 3 Anatomy of the Eye

ScleraThe white part of the eyeball is called the sclera (say: sklair-uh). The sclera is made of a tough connective tissue and has the important job of covering most of the eyeball. Think of the sclera as your eyeball's outer coat.

Look very closely at the white of the eye, and you'll see lines that look like tiny pink threads. These are blood vessels, the tiny tubes that deliver blood, to the sclera.

CORNEAThe part of the sclera in front of the colored part of the eye is called the cornea The cornea is transparent, or completely clear, which lets light travel through ithelps the eye focus as light makes its way through. It is a very important part of the eye, but you can hardly see it because it's made of clear tissue

Aqueous HumorFluid found between the cornea and the iris

IRISBehind the cornea are the iris and the pupil. The iris (say: eye-riss) is the colorful part of the eyeWhen we say a person has blue eyes, we really mean the person has blue irises!

IRIS and PUPILThe iris is a muscle. This allows the iris to control how much light goes through the pupil (say: pyoo-pul). The pupil is the black circle in the center of the iris, and it lets light enter the eye. The pupils will get smaller when a light shines near them and they'll open wider when the light is gone.

TEARSOur tears form a protective layer at the front of the eye and also help to direct the light coming into our eye.

Vitreous HumorBetween the lens and the retina is the Vitreous humor. The chamber is filled with a special transparent fluid that gives the eye oxygen, protein, and glucose (a type of sugar in the body) to keep it healthy.

LensAfter light enters the pupil, it hits the lensThe lens sits behind the iris and is clear and colorlessThe lens' job is to focus light rays on the back of the eyeball - a part called the retina (say: reh-tin-uh).

The lens is suspended in the eye by a bunch of fibers. These fibers are attached to a muscle called the ciliary (say: sih-lee-air-ee) muscle. The ciliary muscle has the amazing job of changing the shape of the lens.

Ciliary Muscle

RetinaYour retina is in the very back of the eye, past the vitreous body.Though it's smaller than a dime, it holds millions of cells that are sensitive to light.The retina takes the light the eye receives and changes it into nerve signals so the brain can understand what the eye is seeing.

Fovea Centralis and Blind spotFovea centralis is the small circular area in the back of the eye where there are densely packed rods and cones. This area is where you can interpret color and images that you see, the central focus spot in the eyeThe blind spot is where you dont have any photoreceptors so you dont see in this area. It is also called the Optic Disc

ChoroidFound in between the sclera and the retinaIt is a connective tissue that keeps both the sclera and the retina together.

What are the parts of the eye?