Rock Island Argus. (Rock Island, Ill.) 1893-1920, 1913-12-19
MYSTERY OF SIGHT
Most Wonderful and Inexplicable
of All Our Senses.

No two persons see precisely alike
any more than any two persons hear
precisely the same. The differences
in these perceptions are due TO the
wide disparities 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
70 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 III
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 il 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 ap-
pear 10 us rs 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: II also distinguishes color And
here is one OF the greatest problems
with which the eye has 10 deal. The
white light OF a ray Of sunshine is
divided by a prism into all Of the
COlors from red 10 violet. and il is one
OF the greatest triumphs 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 retiua.
The eye can perceive waves striking
Il as low rs red and as high as violet,
but there are many rays both above
md 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 Il great influence upon human
beings.
The ultra violet rays are known now
by their chemical action and are term
ed chemical RAYS. while the mira red
rays are heat rays and are known as
such So it is evident that there il
much that the eye does not or cannot
see. even with all 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 Mt the back Of the head. is
the optic nerve. and the fact that II
you have a pain in the bach Of the
head it is probably due TO eye strain is
admitted by all physicians. If you fee
that strain and headache located at the
occiput the first thing TO do is TO CON
suit an oculist 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 eve 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
'STosses the eyes But II is in the
early stages that THE trouble may be
best corrected: otherwise the muscles
become fixed in their error and the de- !
feet Is permanent
II is never too early to put glasses
upUn the child who requires them. II IL
often too late to save the child from
permanent injury OF the most beauti- /
ful. most expressive and most useful
orgsn-New York World.