The sclera and conjunctiva combine to form the white, outer layer of the eyeball. These two outer layers represent the barrier that encase and help protect the eye. The layers extend from the optic nerve behind the eye all the way to the cornea.
Cornea
The cornea is the clear front surface of the eye. The eyelids close and lubricate this portion to ensure that the layer remains moist and clear. This is the first layer that light passes through as it enters an eye.
Anterior Chamber
The anterior chamber is the space between the cornea and the iris in the diagram above. The anterior chamber is filled with an aqueous jelly that gives the front portion of the eye its shape.
Iris
The iris is the colored portion of the eye. The iris is a muscle that has the important job of controlling the amount of light that enters into an eye. In low light situations, the iris becomes smaller making the pupil larger and allowing more light into the eye.
Pupil
The pupil is the black hole in the center of the colored portion of an eye. The pupil is a hole that allows light to enter into the eye. The iris controls the size of the pupil depending on the amount of light the eye is in.
Lens
The lens is the focusing portion of the eye that sits directly behind the pupil. The lens is very thin and flexible at birth, allowing for a tremendous amount of focusing ability. This focusing ability gradually decreases through the course of one's life, resulting in the need for reading glasses about the age of 40 in most people. This is also the area of the eye in which cataracts form.
Vitreous
The vitreous is a jelly that fills a majority of the eye and provides the eye the shape that it has. Often the components of the vitreous jelly will clump together in strands and spots called floaters.
Retina
The retina is the portion of the eye that contains all of the visual receptors. As light passes through the eye, it is focused onto the retina to provide sharp, clear vision. Several visible blood vessels run through the retina, allowing for the only spot in the body where life blood vessels can be seen with out cutting a person open. That is why it is so important for people with diseases like diabetes, high blood pressure, and high cholesterol to have yearly dilated eye examinations.
Macula
The macula is a special spot in the retina with an extremely large amount of visual receptors. This area is where all of our detailed visual work is done. Things like reading, driving, and watching television utilize this area extensively. Diseases that effect this area can be devastating to a person's ability to function in visually challenging situations.
Optic Nerve
The optic nerve is the spot where the nerve that connects a person's brain to his or her eye is seen within the eye. The appearance should be pinkish with a small indentation that is assessed to ensure that one isn't at risk for glaucoma.
