THE ORGAN OF THE JEWELRY AND OPTICAL TRADES,
19TH AND BROWN STS., PHILADELPHIA, U.S.A.

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PHYSIOLOGIC OPTICS

Ocular Dioptrics--Functions of the Retina--Ocular Movements and
Binocular Vision

BY DR. M. TSCHERNING

Adjunct-Director of the Laboratory of Ophthalmology at the Sorbonne,
Paris

AUTHORIZED TRANSLATION

BY CARL WEILAND, M.D.

Former Chief of Clinic in the Eye Department of the Jefferson College
Hospital, Philadelphia, Pa.

This is the crowning work on physiologic optics, and will mark a new era
in optical study. Its distinguished author is recognized in the world of
science as the greatest living authority on this subject, and his book
embodies not only his own researches, but those of the several hundred
investigators who, in the past hundred years, made the eye their
specialty and life study.

Tscherning has sifted the gold of all optical research from the dross,
and his book, as now published in English with many additions, is the
most valuable mine of reliable optical knowledge within reach of
ophthalmologists. It contains 380 pages and 212 illustrations, and its
reference list comprises the entire galaxy of scientists who have made
the century famous in the world of optics.

The chapters on Ophthalmometry, Ophthalmoscopy, Accommodation,
Astigmatism, Aberration and Entoptic Phenomena, etc.--in fact, the
entire book contains so much that is new, practical and necessary that
no refractionist can afford to be without it.

Bound in Cloth. 380 Pages, 212 Illustrations.

Price, $3.50 (14s. 7d.)

PUBLISHED BY THE KEYSTONE,
THE ORGAN OF THE JEWELRY AND OPTICAL TRADES,
19TH & BROWN STS., PHILADELPHIA, U.S.A.

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OPHTHALMIC LENSES

Dioptric Formulae for Combined Cylindrical Lenses, The Prism-Dioptry and
Other Original Papers

BY CHARLES F. PRENTICE, M.E.

A new and revised edition of all the original papers of this noted
author, combined in one volume. In this revised form, with the addition
of recent research, these standard papers are of increased value.
Combined for the first time in one volume, they are the greatest
compilation on the subject of lenses extant.

This book of over 200 pages contains the following papers:

Ophthalmic Lenses.
Dioptric Formulae for Combined Cylindrical Lenses.
The Prism-Dioptry.
A Metric System of Numbering and Measuring Prisms.
The Relation of th