This reference book provides definitions and explanations of technical terms related to optics and ophthalmology. It is designed to be a useful resource for professionals in these fields as well as students and anyone seeking to improve their understanding of optical terminology. The book also includes translations of selected French and German terms. This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work is in the "public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.