The morning call., 1894-05-03
HOW EYEGLASSES ARE MADE
They Are Ordered in These Days
and People Are Measured.
York sur

II is only within the last ten or fifteen years
that the oculists have entirely succeeded the
opticians in the work OF measuring" the human
eyes for eyeglasses. Twenty-Five years ago
an Oculist'S prescription for pair of glasses
was almost unknown in New York. the selec-
ton of glasses being made almost entirely by
the opticians
Now all frst-class opticians bear The same
relation 10 The ocuist that druggists do to
physicians; they I'LL prescriptions only. This
has been brought about, more than by any,
thing else. by the invention. or perfection, of
the ophlhG lmoseope by HelmbolZ. Its use has
specialized" the eye. as The scientists say, 10
such a degree that man whose business it is
10 make glasses cannot possibly do that and
also keep up with The procession of those who
are burning the midnight OH in The study of
basal optic gangliOn. optic chiasm, commissure
OF the optic nerve, stylommalOphOra and thala-
mencephalOn.
The optican sticks to his lens, and that gives
him plenty TO do. He must know all about the
incident and emergent parts of 4 lay of light
they are affected by pieces of glass. and not by
the eye. He must be fine me- chanic capable
OF making by prescription glasses in which are
observed all that the oculist pfescTibeS
TO double convex, double-concave, plano-eon-
veX, planO-cOneaVe. cOncave-cOnveX. and all
those sorts OF things. He knows that the ocu-
list, in examining the patients eyes, has used
an apparatus by which he may have detected Il
variation of liza of an inch from the exact
circle where all exact circle should have ap-
ptdTeQ III the CONSTRUCTION OF I1e eyes, ana
equally exact apparatus for the detection of
other variations, and prescribed in a manner TO
remedy those variations. So the opticlan must
be equally exact I'D his work
The filling OF these prescriptions IS the work
Of artisans, who correspond to The chemists IN
the drugStOTes. They follow the Ocusps fig.
ures relating 10 axis, planes. cOnveXes. con-
caves, sizes and shapes, as the chemists observe
The proportion of drugs called for ana with
equal accuracy. They first fast-n a square OF
glass on the end OF tool. took 1t to another
tool, which looks like a saucer rapidly revolv.
ing, and rough grind the glass. This saucer is
selected by prescription, as it has the curve
called for. The glass Is ground on both sides.
as required. first with rough emery, then fine
emery, and AT last, for the polishing. Ia iron
rouge. paste which seems to be made OF I'M
paipaDly flne iron ore powder.
Even the polishing must b. done so not TO
disturb the exactness with which the glass has
been shaped. so the polishing cloth is fatIened
on the revolving tool, preserving the degree OF
The curve desired. Then he glasses are taken
by other men, who, still working by pfescrip-
lion, fit the lenses with regard 10 the angle of
the axis called for SO the work proceeds until
the finished pair OF specs nose pinchers is
turned over TO The patient, accurate in every
measurement. and adapted TO remedy The i'm
perfection discovered by the ocullsr.
The only fitting which tile opttcian does now
adays not under the direction of the Ocnlist is
the adjustment of the pinceneZ. Big and little
pug aud aquiline. long and short, fat and thin
noses must be equally suited by The spring con-
Meeting the TWO lenses. and in doing that the
opticians clerks 'try on" the glasses 10 the
patients nose as dressmaker tries on a gown.