The Eye A Biological Camera
The eye functions much like a camera. Light passes through the cornea and the
of the eye and is focused on the retina in much the same way that an image is
on the film of a camera.
The cornea and the lens are transparent and bend light rays in such a way that
an image is projected onto the the retina. The iris, the colored part of eye,
the pupil which controls the amount of light entering the eye in much the same
the shutter of a camera controls the amount of light entering a camera. The light
rays then pass through the vitreous cavity that is filled with a clear gelatinous
material and are finally focused on the retina. The image on the retina is then
transmitted to the brain through the optic nerve. This is the basic mechanism of
Anatomy Of The Lens
The natural lens of the eye is located behind the colored part of the eye known
the iris. The lens is like a magnifying glass. The lens is transparent and helps
light rays onto the retina in the back of the eye.
In younger individuals the lens is flexible and can change shape. This allows the
focus at both near and far. As we get older the lens begins to harden and can no
focus. This process starts to occur at about 40 years and is usually complete by
The natural lens of the eye can also develop opacities with clouding of vision.
called a cataract.