System of Diseases of the Eye, Vol. 2 PDF Download

Author: William F. Norris
Publisher: Forgotten Books
ISBN: 9780666264169
Category : Science
Languages : en
Pages : 596

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Book Description
Excerpt from System of Diseases of the Eye, Vol. 2: Examination of the Eye, School Hygiene, Statistics of Blindness, and Antisepsis Green2 and Ewing, of St. Louis, have published a series of test-letters based upon a definite geometrical progression (a: r: 7 95 nearly). They thus obtain a scale in which the intervals are all equal. The numbers on this scale are approximately 50, 40, 32, 25, 20, 16, 5. At five metres eleven different degrees of acuity can thus be noted in terms which are obtained by reducing the fractions 356, 156, - viz., 115, 53 i, if, i, 1 or, in decimals, 1. The same series may also be extended to include greater or less degrees of visual acuity than the above. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This 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.