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.
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
anterior chamber is the space between the cornea and the iris in the diagram below. The anterior chamber is filled with
an aqueous jelly that gives the front portion of the eye its shape.
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.
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 in the surroundings.
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.