John Lythgoe was one of the pioneers of the 'Ecology of Vision', a subject that he ably delineated in his classic and inspirational book published some 20 years ago [1]. At heart, the original book aimed generally to identify inter-relationships between vision, animal behaviour and the environment. John Lythgoe excelled at identifying the interesting 'questions' in the ecology of an animal that fitted the 'answers' presented by an analysis of the visual system. Over the last twenty years, however, since Lythgoe's landmark publication, much progress has been made and the field has broadened considerably. In particular, our understanding of the 'adaptive mechanisms' underlying the ecology of vision has reached considerable depths, extending to the molecular dimension, partly as a result of development and application of new techniques. This complements the advances made in parallel in clinically oriented vision research [2]. The current book endeavours to review the progress made in the ecology of vision field by bringing together many of the major researchers presently active in the expanded subject area. The contents deal with theoretical and physical considerations of light and photoreception, present examples of visual system structure and function, and delve into aspects of visual behaviour and communi cation. Throughout the book, we have tried to emphasise one of the major themes to emerge within the ecology of vision: the high degree of adaptability that visual mechanisms are capable of undergoing in response to diverse, and dynamic, environments and behaviours.

I have been asked to write a brief foreword to this volume honoring Hisako Ikeda, providing a review of the accomplishments in our field over the past four decades, when Hisako was an active participant. This I am delighted to do. It has been a most exciting time in vision research and Hisako has been right in the middle of much of the excitement, publishing on a wide variety of topics and providing much new data and many new insights. Hisako's research career can be divided by decades into four quite distinct areas of inquiry. In the 1950s, as a student in Japan, her research interests were psychophysical in nature, and she was concerned with visual illusions, figural aftereffects, and motion detec tion. In the 1960s, after her move to London, she began electrophysiological studies. Much of her work in the 1960s was concerned with the electroretinogram (ERG), its components, and the use of this electrical response for evaluating spectral sensitivities of the eye and retinal degenerations. This work represented the beginning of her electrodiagnostic clinical work, which continued until her retirement."

I have been asked to write a brief foreword to this volume honoring Hisako Ikeda, providing a review of the accomplishments in our field over the past four decades, when Hisako was an active participant. This I am delighted to do. It has been a most exciting time in vision research and Hisako has been right in the middle of much of the excitement, publishing on a wide variety of topics and providing much new data and many new insights. Hisako's research career can be divided by decades into four quite distinct areas of inquiry. In the 1950s, as a student in Japan, her research interests were psychophysical in nature, and she was concerned with visual illusions, figural aftereffects, and motion detec tion. In the 1960s, after her move to London, she began electrophysiological studies. Much of her work in the 1960s was concerned with the electroretinogram (ERG), its components, and the use of this electrical response for evaluating spectral sensitivities of the eye and retinal degenerations. This work represented the beginning of her electrodiagnostic clinical work, which continued until her retirement."

This book deals with the cellular biology, biochemistry and physiology of photoreceptors and their interactions with the second-order neurons, bipolar and horizontal cells. The focus is upon the contributions made by these neurons to vision. Thus the basic neurobiology of the outer retina is related to the visual process, and visual defects that could arise from abnormalities in this part of the retina are highlighted in the first 16 chapters. Since all vertebrate retinas have the same basic structure and physiological plan, examples are given from a variety of species, with an emphasis upon mammals, extending to human vision. The last four chapters approach the problem from the other end. This part of the book covers a range of clinical conditions involving visual abnormalities that are due to cellular defects in the outer retina. Although the contents of this book do not represent the proceedings of a conference, the concept arose at an international symposium on 'Recent Advances in Retinal Research' which was held at the International Marine Centre in Oristano, Sardinia. We hope that the book will give a coherent, up to date review of the neurobiology and clinical aspects of the outer retina and encourage further integration of these areas. Retinal neurobiology has been an intense field of investigation for several decades. More recently, it has seen significant advances with the application of modern techniques of cell and molecular biology.