The Brookhaven leader. [volume] (Brookhaven, Miss.) 1883-1891, 1883-06-07
NEAR.SIGHTEDNESS.

Of the optical defects, or refractive
errors, which to a greater or less extent
are capable of correction. l will first
mention myOpi1 or near-sightedness,
since it is not only of greater frequency
than any other eye defect, but from its
very nature tends to develop into Sc
rious organic diseases. When l said in
previous article that the human eye
was practically round, | referred, of
course, to that organ in its normal con-
diton. The myopic eye, instead of
possessing this spherical shape is elon-
gated from before backward. The
round eye is so constructed that the
parallel rays of light are brought to
focus on the retina. If this retina be
pushed further back-as it virtually is
in near-sighted eye-the rays of light
will be focused before reaching it. In
other words, there will be no screen
upon which to receive the image formed
by the condensng media, and hence no
impression can be conveyed to the
brain. This variation in the shape of
the organ is not to be measured by
inches hardly by lines. A single half
turn of the adjusting screw of the micro
scope, though producing no visible
lengthening of the instrument, yet
causes the object which was before so
sharply defined to become blurred and
indistinct. So it does not require much
pressing back of the rear wall of the
eye-ball to render our vision decidedly
defective. 1t is generally supposed,
and was even formerly taught, that the
eyes of near-sighted persons necessa-
rily protruded, and that the cornea
in such cases was more convex than
usual. 1t is now known that it is the
posterior segment of the eye-ball which
is at fault-that portion pierced by the
optic nerve, and which, as / have al
ready told you, is the weakest part of
the entire globe.
Near-sightedness is most frequently
an acquired condition, though the
tendency to this defect may, and in the
majority of cases probably does, exist
at birth. That it is one of the unhappy
results of our modern civilization and
our closer application to intellectual
pursuits can not be questioned. No
one ever heard of a near-sighted Indian,
and before our civil war the full-blooded
Southern negro was equally exempt
from this defect The difference be-
tween the eyes of children who attend
the public schools of our large cities
where their brains are developed at the
expense of their bodies-and of those
residing in the country. where at most
only One-half of the year is devoted to
school duties, can not have failed to at
tract the attention of all observant per-
sons. From Germany, Russia, France
and England we have reliable statistics
to prove the relative frequency of these
eye defects. Germany, as we know, is
a land of students, and so common is
myopia in that country that it has long
been impossible to fill the ranks of its
armies without admitting those who are
compelled to wear glasses.
The progressive character of this de-
feet is likewise clearly illustrated by
some statistics furnished by DIR. Cohn,
of Breslau. He examined the eyes of
ten thousand school children and found
results as follows: In the elementary
school about six per cent. were myopic,
in the intermediate school over ten per
cent, in the high school about twenty
per cent, and in the gymnasia over
twenty-six per cent. Other examina-
tions, both in Europe and this country,
furnish us with closely corresponding
data. A very interesting and still more
suggestive series of experiments was
reported from st. Petersburg, a few
years since, where, according to high
authority, thirteen per cent. of the
scholars begin life with inherited myo-
pia. Several thousand children were
selected from the public schools of that
city, and had applied themselves more
or less closely to their books outside of
school hours. Among those who had
habitually studied two hours each day
the thirteen per cent. had increased to
seventeen per cent, while those who
had devoted four hours to their
books twenty-nine per cent. had
become near-sighted; and among
the most Industrious ones and those
who, in their competition for class
prizes had averaged six hours of daily
outside work, more than forty per cent.
had injured their eyes and required
concave glasses for distant vision. One
authority claims that some of the
graduating classes in the highest
schools of the continent of Europe
exhibit the enormous proportion of
seventy per cent. of near sighted
students. In this country, it is
true, we have not yet reached such
frightful figures, but we have already
statistics enough to prove conclusively
that the number of near-sighted or
weak-eyed persons is rapidly increas-
ing, and that each additional year of
study is adding perceptibly to the per-
centage of myopic children; and, mas
much as with the increase of acquired
cases will come corresponding in
crease of inherited ones, it may not be
long before thirteen per cent. of our
population will start in life with this eye
defect. There can be no question that
eye diseases of this character are rapid
ly increasing, and our public schools,
with their forced system of education,
have been justly charged with causing