Excerpt from On Long, Short, and Weak Sight, and Their Treatment by the Scientific Use of SpectaclesI have endeavoured in these pages to lay before the reader, in an easy and practical form, the modern theories of the affections of the Accommodation and Refraction of the Eye, so as to enable him at once to grasp the most salient and important points in the symptoms, diagnosis, and treatment of these diseases. I have purposely abstained from mathe matical calculations, and have confined myself to such simple formulae as I have found most serviceable and ready in practice.I have chie¿y followed the views of Von Graefe and Donders in treating of these affections indeed, we are mainly indebted to their admirable and im portant researches for the scientific elucidation and treatment of this class of eye diseases.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully, any imperfections that remain are intentionally left to preserve the state of such historical works.