This volume on Visual Psychophysics documents the current status of research aimed toward understanding the intricacies of the visual mechanism and its laws of operation in intact human perceivers. As can be seen from the list of contributors, the problems of vision engage the interest and experimental ingenuity of investi gators from a variety of disciplines. Thus we find authors affiliated with depart ments of biology, medical and physiological physics, ophthalmology, physics, physiology and anatomy, psychology, laboratories of neurophysiology, medical clinics, schools of optometry, visual...