The author of the book is a professor of bionics at the University of Edinburgh, one of the world's largest specialists in vision psychology. Answering the question, "how does the brain extract information about the outside world from a certain pattern of spots of light on the retina of the eye," R. L. Gregory competently and fascinatingly talks about the connections between the most important factors of perception, about the most complex multifaceted process of visual thinking.