Excerpt from Why Do We Wear Spectacles?: Read Before the Medical Society of the State of California, at the Annual Session Held at Sacramento, October, 1871C., cornea, A. H., aqueous humor, C. L., crystalline lens, V. H., vitreous humor, S. C., sclerotic coat, 0. C., choroid coat, , R., retina, 0. N., optic nerve, C. M ciliary muscle, 0. P., ciliary process, S. L., suspensory ligament of the crystal line lens, I. A., iris, when the eye is accommodated for near objects, it is seen to be nearer the cornea than when the eye is at rest or looking at distant objects as at I. R. N. V., the upper half of the crystalline lens, down to the break in its anterior surface, shows it more convex and thicker - its condition when the eye is receiving divergent rays from near objects - than the lower half D. V., which is seen to be less convex, its condition when the eye is at rest or receiving parallel rays from objects eighteen or more feet distant.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.