A History of Vision Science

Introduction

Vision science is the science dedicated to the interdisciplinary study of visual perception and the visual system. Visual perception is the ability to interpret information and surroundings from the effects of visible light reaching the eye [9]. Many years visual perception was the domain of a man, but nowadays with the appearance of cheap cameras and powerful hardware computers starts to advance. The theory and the observations on visual perception have been the main source of inspiration for computer vision (also called machine vision, or computational vision). Special hardware structures and software algorithms provide machines with the capability to interpret the images coming from a camera or a sensor. Artificial Visual Perception has long been used in the industry and is now entering the domains of automotive and robotics.

Throughout recorded history, mankind has wondered at the world and sought to understand it. The study of vision and light has been central to understanding nature. Many scientists, philosophers, and scholars of antiquity considered vision a supreme sense, and understanding of nature of vision and light as keys to unlocking the secrets of the universe. Their curiosity into the nature of light and visual processing in eyes gradually developed the field of vision science, a field in which men of understanding put their ideas and predictions to test and surprised themselves as much as others of intricacy of optical phenomena. Their contributions to the field laid the foundations on which modern field of vision science stands today. Here the brief history of development of vision science and major contributions in the field from classical antiquity are discussed as well as modern state-of-the-art.

Vision Science in Antiquity

Classical antiquity refers to the golden age of Greco-Roman civilization that lasted approximately from 800 B.C. to 500 A.D. The birth of philosophy in ancient Greece played an important role in the development of science of optics. Ancient Greek and Roman philosophers developed optics as one of the branches of the natural sciences. Understanding mechanisms of vision and light was very important to Greek and Roman philosophers because vision was considered the most important sense, and the idea of curing an eye disease was considered even more miraculous than it is today. Because Greek and Roman philosophers were also highly religious, they attempted to explain vision not just rationally but in a manner that was compatible with their religious and spiritual ideas. Some of the ancient theories of vision and optics described below sound very strange to us when we study them, but to Greeks and Romans of the time, these theories were remarkable achievements of their philosophers as they brought them closer to understanding their world.

Democritus (460 B.C. - 370 B.C.) developed the idea that in order for human eye to see an object, the object must physically come into contact with the eye. This idea is referred to as intromission theory. The object accomplishes this by pressing the air between the eye and the object. The pressed air then holds the color of the object and travels to the eyes where it comes into contact with them, resulting in vision. Democritus also studied the anatomy of the eye and figured that the eye is composed of water, and water not only fills the eye but can also travel through the optic nerve located in the back of the eye. Democritus also claimed that there are four basic colors: white, black, red, and green. The rest of colors are produced by mixing these four basic colors.

Epicurus' (341 B.C. - 270 B.C.) theory was similar to Democritus' theory in a way that he also claimed that the object seen must come into contact with the eye. However in Epicurus' opinion, vision occurs when particles from the object travel to eyes and contact them rather than pressing the air. Although this would result in gradually shrinking the object, the object does not shrink because particles from surroundings fill empty spaces in the object.

Plato (427 B.C. - 347 B.C.) took intromission theory developed by Democritus and Epicurus and enhanced it with a new theory called extramission theory, which states that vision occurs when light comes out of the eye and hits objects outside. Thus, eyes are light producers. Plato imagined light from a ball of fire emanating from the eye and combining with sunlight to hit the object seen. When this occurs, object releases "flame particles," similar to the idea of Epicurus. The colors that we see are those flame particles. Flame particles come in different sizes, which give rise to variations in color. Bigger particles generally produce darker colors, while smaller particles produce lighter colors.

Aristotle (384 B.C. - 322 B.C.) did not believe his predecessors'