This book aims through scientific knowledge, to present in an easy, concise and basic way, the most frequent diseases that cause changes in different ocular structures, some of them triggering severe alterations of vision, and even blindness.I am confident that this study manual will allow a better evaluation, making a more appropriate analysis, helping to have a better understanding of the problem.With this brief introduction, I would like to make this work available to you, hoping that it will be a means for all of us to improve the quality of technical collaboration in Ophthalmology, for the benefit of the patient and thus achieve our intention.