Produced by Ian Deane, Josephine Paolucci and the Online Distributed Proofreading Team at https://www.pgdp.net. CLINICAL INVESTIGATIONS ON SQUINT A MONOGRAPH BY DR. C. SCHWEIGGER, PROFESSOR OF OPHTHALMOLOGY AT THE UNIVERSITY OF BERLIN TRANSLATED FROM THE GERMAN BY EMILY J. ROBINSON EDITED BY GUSTAVUS HARTRIDGE, F.R.C.S. LONDON J. & A. CHURCHILL 11, NEW BURLINGTON STREET 1887 TRANSLATOR'S PREFACE The subject of Squint is so interesting that we venture to think an English rendering of this exhaustive monograph will be acceptable to many ophthalmic surgeons and students. While adhering as far as possible to the spirit and style of the original we have not hesitated here and there to give a somewhat free translation. This has been partly necessitated by the difficulty of finding an exact equivalent in English for all the terms used in the original text. In the German Edition the old system of inches is used. We have (with the consent of the author) altered these to the dioptric system. E. J. R. G. H. PREFACE _Amicus Plato, amicus Socrates, magis amica veritas._ May my friends and colleagues, whose views differ from mine, read the following observations without prejudice. A fact, which does not agree with the system, is generally worth more than theory, still it is very difficult for even the most important fact to find recognition if it contradicts received opinion. For theories and dogmas are narcotics, which are necessary to men; some flatter themselves by composing them, while others content themselves by satisfying their own craving for a creed. Reasonably applied, they may be useful, but the boundary line is only too easily over-stepped. It is the task of science to observe also whether theories correspond with the progress of facts. The present reigning theory on strabismus will have to submit to various limitations; on the other hand, we are ready to leave to the scholastic science of medicine and its followers certain dogmas which remain unproved and which have nothing but the fact of their existence to recommend them. The small compass of the following treatise proves that it was not intended to exhaust the rich literature on the subject; I have only referred to the same where it appeared to me necessary for the interest of the work in hand. Above all, it has been my endeavour to treat the subject of this treatise (which occurs so frequently in practice) in a way intelligible to every physician, at the same time, however, to bring sufficiently into notice those facts and views which are of value to my special colleagues. C. SCHWEIGGER. BERLIN. INDEX TO CONTENTS. INTRODUCTION. PAGES