Violence entails inflicting emotional, psychological, sexual, physical and/ or material damage. The violence arising from war or actions of civil insurgency have dramatic impacts on the psychological and physical well-being of countless people. Perception is a process for obtaining knowledge of the world, and more than 80 per cent of it is accounted for by vision. The anatomical and physiological basis for vision is one of extraordinary complexity and delicacy, and it is mainly since the early 1960s that a detailed knowledge of how it works has been attained. Important theories in the field of vocational and career development have been summarized by S. H. Osipow. D. E. Super's original self-concept theory, which viewed vocational development as being inextricably linked to the development of a person's self-concept, was subsequently expanded to include consideration of the changing life roles of individuals throughout their life-span.