Year: 1875




A Chapter for nIIddIe-Aged People.


Tt is generally those whose sight is
already impaired who feel any interest
in its preservation for in this respect
there is that same effort to be wise too
late which distinguishes so. many of
our proceedings, and which popular OBJ
servatiOn has cryEtallized into the
homely proverb, Locking the stable
after the steed is stolen" Yet surely in
vision, moro than anything else that
pertains to our physical welfare, is
prevention better than cure because
here the loss that is not prevented can
never be cured and what the present
prodigaIity wastes, no future can re-
gather.


Though there are numerous excep-
tions, yet with the large majority the
eve begins, somewhere between so and
35 years of age, to lose a part of its
bending power. The ball and crystal
line lens get fiatter, and the rays of
light, instead of being gathered tn
gether. and drawn inward with suff1-
cient force upon the retina. are scat
tered and the light confused. If the
eye is close to the object, it catches the
divergent ravs at their source, and
being weak and unable to manage them,
the habit is involuntary acquired of
holding the newspaper or words at a
distance in order to get rid of the un-
manageable part of the light. This is
the first symptom of decaying sight,
and should never be neglected.


Donders-now universally accepted
as the highest authority-says when
ever If is necessary to hold a fine type
eight inches from the eyes in order to
read it the prudent person will at once
give his eyes the assistance of a glass
of lower convex power which, how
ever must be worn when occupied in
close study or work, and in whose selec-
tion the advice of a good Oculist is
always worth the fee.


The curved glass interposed between
the eye and the light does part of its
work and the organ too weak for the
entire task can, however, complete what
the glass begins. But as the eyes get
flatter with age, glasses more and more
convex will be needed; for the preser-
vation of the sight demands that they
should be constantly guarded from
unnatural efforts.


When once spectacles are required
from natural decay of vision, the dis
cas- 3, like age, is incurable; all glasses
can do is to "linger and linger it
out" A confusion of the letters in
reading or writing is an imperative
order for older spectacles, but If the
eyes are used economically, and pro-
tected from sudden and strong lights,
the same focus will often serve for sew
eraI years.


In choosing a pair of spectacles, see
first that both eyes have the same focus.
The left eye has habit of tagging be-
hind and leaving the right eye to per-
form the largest share of the work, In
which case the glass suitable for the
right eve might be injurious to the left,
since the sight has worn unevenly.


The correct focus found, it is very
important that the center of the glass
and the center of tie pupil be directly
opposite each other. In this respect the
selection of glasses is difficult, for the
space between the eyes differs IN almost
every individual, yet very little atten-
tion is paid to this fact In the manufac-
ture of the frames.


To be sure that the glasses are with
out speck or flaw hold them before the
flame of candle, and to prove their
uniformity of substance and exsctness
of shape, 1t is only necessary to raise
them from the book slowly toward the
eyes, and if the letters are not distorted
they are correct.


On no account buy glasses that do
not fit the eyes, or at once relieve the
sight, because the seller insists the
eyes 'will get used to them" The
eyes, indeed, may be forced into har-
meny with new refractions, but it en-
croaches fearfuIly on the resources of
other years, and they are urged q long
step onward to darkness and decay.
M. Jourdain was not the last to wear
tight boots bacause his shoemaker as
sured him the pain was all imaginary.


Lenses made of the best optical glass,
and carefully ground by the best max
ers, are now nearly universally used in
place of pebbles. Pebble-except that
they are harder to break-have no real
advantage over glass, and they are very
much dearer. Where comfort and
effectiveness are regarded more than ap-
pearance, the rims should be neither of
gold nor of tortoise shell, but of light
metal. Those made in Wolverhamp-
| ton, England, are now so perfect and OF
such dainty and exquisite workmanship
| that, with their lenses and all complete,
they weigh under a quarter of an ounce.
It is a very foolish idea that the years
snatched from the use of glasses are SO
much added to sight. The reverse is
| the case if the sight is strained, yet il
| is every opticians experience that many
| delay until their first pair of glasses is
| the last On the list. Consequently


when the power of these is exhausted,
/ nothing remains for the unhappy victim
/ of vanity or ignorance but darkness
/ visible" for the rest OF life.


There is a popular fsllacy, often very
/ fatal to vision In it's results, that short
! sighted people do not need glasses, and
| that their sight will improve with age,
/ IF it does, the pOssessor of it will need
no one to inform him of the fact. But


if it does not do so perceptibly-f, or


the contrary, the infrmity continues tC
progress or even TO remain IN about the
| same condition-Donders says trouble
| some SYMPTOMS will set In at from 81
| to 60 years of age, if not earlier and


the power of sight be lost either from
| the separation OF the retina from tho
choroid, from effusion of blood, or from


atrophy OF the yellow spot.


Short sight is sometimes hereditary


but it is a well-ascertained fact tina


far the greater majority nf such case


are found IN the cultivated classes, en(


chiefly among the students and literar,
people. Among 10, 900 recruits for tn


English foot-service, not a dozen wer


rejected for this imperfection, while Il


one college at Oxford thirty-two short


sighted men were found out of 127
(Donders on the Eye; London, 1884
This enormous difference points to th
] one great cause-tension Of the eye