The ultimate purpose of computer graphics is to produce images for viewing by people. The intrinsic complexity of the physical world and the limitations of display devices make it impossible to present a viewer with the identical patterns of light that would occur when looking at a natural environment. Artists and illustrators have developed empirically a broad range of tools and techniques for effectively conveying visual information. One approach to improving the perceptual effectiveness of computer graphics is to utilizeThe remainder of this chapter provides a partial overview of what is known about visual perception in people. The emphasis is on aspects of human vision that are most relevant to computer graphics. these methods in our automated systems. Vision is generally agreed to be the most powerful of the senses in humans. Vision produces more useful information about the world than does hearing, touch, smell, or taste.