Evening star. [volume] (Washington, D.C.) 1854-1972, 1880-02-28
OLD EYES AND NEW.
Philadelphia Press.]
THE sixth sge shifts
Into the lean and slippered pantaloon


ten Is obligatory. There are, of course, those
who wear them because it is the fashion, or from
belief that it improves the looks and lends a
cases are few, and 1t is well they should be- for
by using glasses when there is no absolute ne
cessity is really sowing the seed Of disease in
81 have left my glasses at home" is an ex-
preston frequently heard, and subjects the per-
son 10 considerable inconvenience and annoy
ance. Certainly, they may be able to borrow
d pair from a friend. which will serve the pur-
pose for the time being, but 1t Is seldom that
two persons have sight so exactly alike as to be
able to use the same lens with any degree Of
comfort.
It is a noticeable fact that more young per-
sons are now obliged to resort to the use Of
glasses than formerly. This is partly owing to
1t is not to be denied that there arc beauties
which may be enhanced by eyeglasses as well
there that would not say that the rims Of shin
ing gold, of blue steel or prosaic rubber do not
bring out in brighter relief charms of a fine
deep, 50 appealing as the nearsisnteds T6 he
eyes Of black, do they not gain additional charm
Dehlnd the crystal screen? We will leave the
answer to those better able to Judge Of these
things than we are.
1t is very easy to enter the store Of some of
and ask TO be fitted with a pair Of glasses. That
worthy looks profound, asks sundry questions,
perhaps places before your eyes large card
upon "u1Cu 10 UlG alpQdOeJ III ldTR6 anu
small text, almost bringing one back to youth
ful days. when we first began to read The
glasses are given and the sight tested. At last
the right focus is found, we are satisfied. and
after satisfying the optlcian with his price de-
part But how few stop to think where and
when spectacles were first introduced or the
amount OF labor and machinery used in their
manufacture.
Spectacles were supposed to have been in
vented as early as the thirteenth century, and
are ascr1bed by some to Alexander di Spina, q
FIOTpntinp monk who died ahOut
or to his fellow tOwnsman, Solomon Armatus
They were also mentioned in sermon preached
by one Jordan d hyalto In the year 1906; but
1t Is more probable that the knowledge of them
came through Saracen named Alhazen, about
the same time. Roger Bacon was also credited
with the invention, but there seems to be no
foundation for the assertion. The Chinese, we
are told, have for ages used spectacles for the
relief of defective vision. At first they were ex-
ceed1ngly clumsy, both in the lenses and also
in the frames, which were, for the most part,
made of horn or tortoise shell. Very little i'm
provement was made until the beginning of the
present century, when light metal frames were
substituted From that time until the present
rapid strides have been made in their manufac-
ture, until the spectacle of to-day is as near per-
lection as 1t can be. Quite large business was
at one time transacted in importing these goods
from England, where they were chiefly made,
Wolverhampton being the principal place.
But English glasses are now rare the market
being supplied by American manufacturers, the
glass used being of superior quality.
Spectacles are of various kinds For long
sighted persons (presmyopic) whose Imperfect
vision Is due to too great atneSS OF the lens and
cOrnea. either p1anO-cOnveX lenses or meniSci
are employed. Both Of these magnify objects
and render those which are nearer more distinct.
For near-sghted or myoptc persons, whose cor
nea and lens are too convex, either piano con-
cave or concavo concave glasses are used. Plain
glasses colored blue, green or smoky, are used
by persons with eyes which are too sensitive to
vex lenses and are used by persons whose eyes
have been operated upon for cataract.
Considerable attention has of late been given
to the examination of each eye and the careful
adaptation of each lens to the needs of the eye
1t Is to serve, as it is very common especially in
myopic or near-sighted persons, to find differ
ent degree OF abnOrmal1ty in the two eyes.
Many spectacles are sold which dealers pretend
have their surfaces ground to parabolic curve,
but the construction Of such lenses Is both diff
cult and expensive. If, however, they are prop
erly made, there Is certainly less Of spherical
alteration.
Persons under the age of forty years. in good
health and having eumetropic eyes, do not
need spectacles; those with hypermetropic eyes
should wear convex glasses sufficiently strong
to correct the hypermetrop1a; those with myopfc
eyes should select the weakest concave glasses
Astegmatic eyes should be fitted only after care
full examination by an oculist. Glasses for dis
tant vision, as In myopia, should be set high
In presmyopia, should be lower and inclined
This is necessary for the simple reason that the
way in which glasses operate to assist the sight
Is ny COiupcuSdClIS lOF Uuc failure OF certain
muscles concerned In the use OF the eye and full
filing their functions.
1t is the prevailing notion among those who
use these aids to vision that the opticians from
whom they purchase these articles are the max
erS OF them, but this IL not so. No opticIan
really knows how to manufacture pair of
spectacles. While some may know the theory,
when asked to demonstrate it In practice they
are Immediately at loss. Although there are
to-day few of the old-time spectacle makers
who can be found sitting in their stores grind
ultimately making lens the business is not
carried to any great extent. opticians confiuing
themselves principally to fitting glasses after
they have been manufactured.
II was not until a few years ago that machin-
cry run by steam power was brought into use
for the purpose. As in everything else in which
the same power was first used the idea was con-
sidered impracticable, in consequence of the
nature of the material, but today our own Key
stone state possesses the largest and most COM
plete steam spectacle factorytn the world. The
white lens In use In the ordinary spec
tacle OF commerce is made of the common win
dow pane glass rolled into sheets, sometimes it
Is made into balls. From these are cut pieces of
about one and quarter to one and half inches.
in size, they are then taken into the grinding
room and each piece cemented securely upon
what Is called lap of semt-clrcular shape.
or saucer. into which fine emery powder is In
PRODUCED and subjected to a swift rotary mo-
ton. The gradual curve in the lap gives to
the glass as 1t is ground a corresponding shape
until the desired center Is reached; the lap is
then taken out and subjected TO warmth,
which melts the cement sufficiently to
permit the glass being removed and
turned upon the opposite SIDE, when the same
process Is renewed. This being completed the
lenses are detached again from the lap are
taken to another department, where they are
shaped to fit the frames. This is accomplished
by machine of extreme dehcacy. Each piece
of glass is put separately upon rest, when a
diamond is brought to bear upon it, moving In
the form OF all oval thus cutting the desired Size;
but the edges, of course, are rough and sharp,
and must be beyeled. For this purpose they
are turned over1nto another set of hands. mostly
girls, who have charge of the gr1ndStoneS
which are about six inches in thickness Each
operator Is provided with gauge; the glass is
taken between the foref1nger and thumb and
held sufficiently sideways to produce half the
desired beve; when this Is attained it is again
turned and the other side of the bevel COM
pleted. During this process 1t is constantly
gagged in order to ascertain that the frame will
close upon 1t without too much pressure which
would break the lens
The next process to which the lens Is subject
ed is that OF focusing, - and requires extreme
care. The person having this department to
attend to is placed In small room alone; across
the entrance is hung curtain, which is only
drawn aside sufficiently to admit the required
amount Of light from a window several feet
away, upon one of the top paneS Of which Is
placed piece Of heavy cardboard with small
hole cut in the center, representing the Bulls
eye of target. Through this the rays of light
shine upon the lens in the hands of workman,
and is reflected through it to dark background.
The lens IA then moved hack and forth rInoTi an