The
best way to understand how the eye works is to compare it
to a camera. Like the eye, a camera creates images by focusing
on an object and allowing specific amounts of light to pass
through a hole that creates a visual impression on film.
In vision, light enters the cornea, much like a camera lens,
and is focused. (If you have cataracts, your eye lens is
cloudy - The surgeons at Halpin - Poweleit Eye Center, located
in Cincinnati Ohio, specialize in the detection and treatment
of cataracts.)
Next, the light passes through the pupil where the iris
works as an aperture to adjust the amount of light allowed
to enter. Light then enters the lens where the remaining
focus is achieved. The shape of the lens can adjust (either
thinner or thicker) by tensing or relaxing the muscles of
the eye.
The final destination of this focused light is the retina,
which functions as film and converts the light into a signal
using the cells, called rods and cones. These signals travel
to the brain where, in essence, the film is developed into
an image - giving the miracle of sight. |