Purpose
Our eyes are tools of the brain,
designed to gather, guide and filter light for ultimate conversion
into the brain's own language.
All components of the eye are designed to
support and focus light on the retina with its millions of
photoreceptors and nerve fibers lining the back wall of the eye.
Everything in the eye develops from three
basic layers of tissue: the sclera (an
inflexible white tunic that encases the eyeball; the choroid,
the eye's blood supply, and the retina. Shown
below (top) are a diagrammatic sketch of the eye, with its various
parts, and (bottom) a colored photograph of the retina.
A photograph of a living retina
(bottom). The large pale circle is the optic disc where
arteries and veins enter the retina. The darker red area is
the macula, used for seeing color and detail.
[ Diseases ]
