This book, through scientific knowledge, aims to present in an easy, concise and orderly manner the most frequent diseases and disorders of the posterior segment of the eye since some of them may cause alterations so severe that they can even lead to blindness.I trust that this book will make a better evaluation of degenerative disorders of retina and choroid, making a more appropriate analysis with a large number of photos and images, which will help to have a better understanding of the problem.This work takes its place as one of the most comprehensive yet readable books on the retina and choroid subjectand with its degenerative disorders.I have tried to follow some selection criteria with the pathologies that may be more frequent in the retinal speciality practice, so that this treaty is dynamic and flexible for all specialists and adapts in the best way in each pathological situation.Distinguished University Professor Dr. Sir Luis E. Abad