The Punta Gorda herald. [volume] (Punta Gorda, Fla.) 1893-1958, 1913-11-27
MYSTERY OF SIGHT
Most Wonderful and InexpIicable
of All Our Senses.
LIMITS OF THE HUMAN VISION.
There Are coIors All About Us That
the Eye Cannot See, az We Cannot
Distinguish Beyond the Extremes Of
the Spectrum Red and Violet.

Distinguish Beyond the Extremes Of
the Spectrum Red and Violet.
No two persons see precisely alike
any more than any two persons hear
4 precisely the same. The differences
in these perceptions are due to the
wide dispnrities not only In the organs
Of vision and hearing. but also to the
differences In mental makeup of the
individuals.
There are more unsolved problems as
to sight than any other sense. 1t is
the most wonderful and at the same
| time the most inexplicable sense that
we possess. Every school child is
taught that we see because rays OF
light reach the retina of the eye after
passing through the transparent cor
-nea. that curved surface which Is in
direct contact with the external air.
the aqueous or watery humor. and the
crystalline and vitreous humors.
The eye is thus made up Of three
separate lenses. through which the
light passes before reaching the retina
When observed from outside 1t is plain
that all the images appear to be re-
versed In the eye. We see everything
upside down. but In some way this
reversal is corrected, so that things APP
pear to us as they should. though this
simple point has not yet been explain
ed by the most advanced science.
But the eye sees not Only images and
light: 1t also distinguishes color. And
here Is one of the greatest problems
with which the eye has to deal. The
white light of ray of sunshine is
divided by prism into all of the
colors from red to violet. and 1t Is one
Of the greatest trinmphs OF modern
optics to have proved that what we,
call color is nothing but the speed
with which some parts OF the ray Of
sunshine strike upon the retina.
The eye can perceive waves striking
1t as low as red and as high as violet.
but there are many rays both above
and below the red and violet. the ex-
tremes of the spectrum. as they are
called The human eye cannot per-
ceive these because the lengths of the
waves or the frequency with which
they strike upon the retina are too
great or too small for the human or
gan. Yet they are most important. ex-
ercising a great influence upon human
beings
The ultra violet rays are known now
by their chemical action and are term
ed chemical rays, while the infra red
rays are heat rays and are known as
SUCH So 1t Is evident that there is
much that the eye does not or cannot
see. even with al the mechanical aids
which have been provided in telescope,
microscope. etc.
What really carries the message of
vision to the brain center of vision.
which is at the back Of the head. is
the optic nerve. and the fact that II
you have a pain in the back of the
head it IS probably due to eye strain is
admitted by all physicians. II you feel
that strain and headache located at the
occiput the first thing to do is to con-
suit an ocullst and get the glasses
which will correct the error of vision
Your eyes may be wrong in any num-
Der of ways. Either there may be a de-
feet In some one OF the lenses or the
nerve may have become weakened or
the muscles of accommodation by
which the eye is focused may be
wrong The last is probably the com
monest Of troubles and may be easily
corrected II promptly taken in hand by
an expert.
Cross eyes are only defects of mus
cular control. and the latest researches
point to the necessity for correcting
this defect as promptly as possible.
Many parents make the fatal mistake
of not calling In the specialist even
when they notice that an infant
crosses the eyes" But It is in the
early stages that this trouble may be
best corrected: otherwise the muscles
become fixed in their error and the de-
feet Is permanent.
1t is never too early to put glasses
upon the child who requires them. 1t is
often too late to save the child from
permanent injury of the most beauti-
full. most expressive and most useful
organ--New York World.