Page 94 - Miracle in the Eye

long with the improvements in medical technology,
we have come to realize how miraculous the human
eye actually is. Whenever a new discovery about the
eye is made, a new camera or optical system based on
it is released very soon afterwards. The camera is the
most common artificial impersonation of the eye and the
human visual system. But however much technology may advance, no
man-made optical equipment, including computerized cameras, can com-
pete with the eye. No electronic systems have been anything more than
primitive copies of the eye.
To support this claim, compare the features of a camera and the
human eye.

The Camera
A basic camera lens is designed to focus a three-dimensional world on
a two-dimensional surface. As a result, the picture is inverted and consid-
erably smaller than the real-life scene.
Similarly, the eyes' cornea and lens are designed to focus the image
inside the human eye, whose interior is like a dark room—although we
shouldn't forget that this "room" is alive. The tissue whereon the inverted
image is formed is called the retina. It works like the film in a camera, al-
though its job is to transmit the images it receives to the brain, in the form
of electrical signals.

Focus Adjustment
Before taking a photograph, the first thing you should do is focus the
image to make it clear and sharp. In the eye, our lens adjusts itself accord-
ing to its distance from the object we're looking at. With a camera, and also
on instruments like microscopes and telescopes, adjustments must be done
by hand, unless the machine is automatic. In each instance, this focusing
takes some time.
In the human eye, however, focusing takes far less than a second,

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