This paper relates the modern concepts of vision to performance areas such as reading. The sensory and motor aspects of vision, the interaction of vision with the other sensory-motor systems of the body, the development of the visual process, and the relation of vision to learning are described. The paper also demonstrates how the many functional and biological aspects of visual behavior aid in relating man to his environment in terms of understanding, action, and communication. It also stresses the primary of the process of vision in all these interactions.