Pittsburg dispatch. [volume] (Pittsburg [Pa.]) 1880-1923, 1889-10-12
WONDERS OF TIE EYE.
Curious Things About Natures Camera
Progress of OphthaImIc scieuce-Danser
In Imperfectly Fitted Glasses-Myopia

Progress OF Ophfhaimic Science-DanGe1 Ge1
In Imperfectly Fitted Glasses-Myopia
and Farsightedness.
~ would like to examine the interior of the
eye," said the oculist. But, when he perceived
slight shrinking on the part of the reporter
whdhssumed for the time the role of patient
he smillngly added: "You need not be alarmed
it will not hurt you a particle" Then picking
up little disk-shaped mirror with hole
through the center he led the patient into o
dark closet, and after lighting bright gas jet
told him to sit down on the chair Immediately
beneath it. Next he himself sat down oppo.
site, so that the knees of the two touched, and
held the small round looking-glass in front Of
bis own eye, like an eyeglass, with the mirror
side outward, in such a manner that It reflected
ray from the gas jet straight into the pa
TENTS eye through the pupil. He could direct
the ray easily enough, inasmuch as he waslook-
ing along it through the small hole that pierced
the center of the disk.
your eye and look through it at the eye Of a
person seated in front Of you you will get no
ton of the way in which the oculist operated.
Suppose the button-mold has quick-silvered
glass on the surface turned toward the object,
and you will perceive how easy it would be to
throw ray reiecred from q light above the
other PERSONS head directly in that other per-
sons eye, and to watch, through the hole in the
a
Wonderful Photography,
This was what the oculist was doing with the
mirror disk. The ray it reflected entered the
patients eye. through the pupil, and lighted
up the interior very much as dark room is
lighted up by bulps-eye lantern shining
through doorway from outside. Just as the
lantern might be turned about this way and
that, to illuminate various parts Of the darkened
chamber beyond the doorway, SO the little
looking glass was manipulated between
the frefnger and thumb of the physician,
as he held it before his own eye, in such 3
manner as to reveal to his view every portion
OF the inside Of the ocular camera obscura-for
such the eye is; very much like the camera Of
the photographer in its construction and mode
% OF WORKING: and 1t has been found out quite re re-
so-called ocular purple" in the eye actually
produces the pictures of objects seen, on the
nerve-screen that lines the organ, by chemical
process very much like that employed by the
photographer to bring out the lines Of his
negatives. Possibly, some day, by studying
natures method, the sun-print artist may learn
how to photograph colors as the eye does. Who
knowsf
What is the little round mirror called with
which you examined my eyes insidef" asked
the patient while the oculist was engaged in
fitting glasses Of various strengths into huge
nose frame for trial.
To that little instrument" responded the
surgeon, rs due nearly all Of the progress
made in ophthalmic science since the days of
yet, as you see, It is nothing but small, round
mirror with hole through it. It is called the
'oPhthalmoscope,' and was invented by Helm
holtz in 1852
Modern OphthaImic Science.
"so few years ago as that very little was
known about the eye beyond what the old
Egyptian physicians were acquainted with.
They were familiar with the structure of the
organ, through dissection, and they even per-
formed operations for cataract. That disease,
you know, is merely a clouding of the crystal
line lens which lies just behind the little hole
in the iris, called the pupil and serves to bring
the rays Of light that enter the eye through the
pupil to focus on the nerve screen behind.
1t Is at this focus that the picture of the object
seen Is formed, like phonograph But If the
lens, which Is like q wee bit of convex glass, is
rendered opaque by any cause it is termed
cataract and the lens itself must be gotten
out or the way, so as not to interrupt the light
rays. So, nowadays, it is cut out of the eye and
removed, while in ancient Egypt 1t was simply
pushed down by needle into the lower part Of
the eye, frequently to occasion subsequent in
hammation and loss Of sight However, as to
the ophthalmoscope, was going to say that it
aHorded the hrst means ever discovered for
studying the interior Of the living eye. From
that point modern ophthalmic science really
took its rise, and there is not much about the
eye to-day that Is not understood"
Near -sightedness Among the Ancienfs.
"Were people afflicted with near-sightedness
In ancient times?"
"Oh, yes; though probably not to the same ex-
tent. We read, write and study more than the
ancients did, and for this reason nearsight Is
more common with us, for it is the excessive
use Of the eyes at the near point that propa-
gates the trouble. In old times troubles with
the eyes were regarded as Affections sent by
heaven, for which there was no cure. Nero,
who fiddled while Rome was burning, was SO
that, although he had the very
best seat in the amphitheater at the gladiator
shows, he could not see what was going on.
One day he discovered that certain concave
emerald in his collection of jewels aided his
vision materially, and from that time he al
ways carried the emerald about with him and,
when he wanted to see anything at distance,
looked through it. He regarded the stone as
talisman and supposed that its properties were
magical"
is it true that every person needs spectacles
at some period of hfer'
Decidedly, If the person lives to be As years
Of age. At that ago, or at any rate before so is
the crystalline lens which is of the
of jelly in childhood, has gradually
hardened to the consistency of wax, so that the
muscles which change the focus of the eye for
various distances, by altering the shape Of the
lens, find It difficult to do their work"