Vision and Visual Perception

This book is about vision and visual perception. Vision is about insight, and visual perception is about cognition. These two are the two legs on which the book is based. They come together in the body. The focus is on human consciousness, where all ideas of insight and cognition are processed. Therefore, the body is also in a literally sense the body, the bulk, of the book. On top of the body one finds the head, in this case the unity of it all, the harmony, and even, in a tentative way, some ideas about the spiritual aspects, about 'seeing the light'.

In its most essential form, vision is the human function that converts information from the outside world into conscious experien¬ces. It goes without saying that this implies that consciousness, human consciousness, plays an essential role in the considerations, as will be clear from the extens¬ive discussion of the concept in this book. The major part of the book is about human consciousness. In the most practical cases the information from the outside world is embedded in electromagnetic radiation that is processed by the the visual sensory apparatus, involving the related ele¬ments of the nervous system and of the brain.

Many scientists explain that their career is based on curios¬ity in some area that began at a very early age. Some astro¬physicists are known to tell stories that their interest began when they saw lunar landings on their home television. My life shows a similar course of events. I still have very acute memories of aspects of vision and visual perception, and more in general of occasions that would nowadays classify as empirical physics at a time long before I could read, in fact before my fourth birthday. Some of my first recollec¬tions as a very young child of about three years of age were already related to the questions as how vision works, and after a long life where I was professionally engaged in the matter, the questions are still there. They are phrased differ¬ently now of course, but in essence they are still there. The questions refer to how do we see, and how do we recollect what we have seen, and how do we know that we have seen something, how can we understand what we see, or what we know what we see, and what may we do with the things we have seen. Needless to say that in many instances what is said about vision might relate also to other sense organs like hearing, smell, taste, and so on. However, I will stick to vision, with the possible exception of some multi-channel experiences.

There is a reality 'out there' and a reality 'in here'. All knowledge about the reality 'out there' comes to us via the senses. As senses are never fully exact, we have to be satisfied by an approximation. Visual perception will in all likelihood provide a quite large amount of useful information about the world 'out there', but one never can rely on it in order to come to hard conclusions about the outer world. Sensory perception is the only window we have towards the reality 'out there'. We have to be satisfied that the window distorts the view.