Oculomotor systems that regulate eye movements play an important role in accounting for certain qualities of visual experience. They are implicated in a wide array of perceptual topics, from apparent size, depth, and distance, to apparent slant and vertical orientation. This text emphasizes the role of oculomotor systems in perception, and discusses the basic characteristics of such oculomotor systems as those controlling vergence, pursuit, the vestibulo-ocular response, and saccadic eye movements. This volume introduces fundamental concepts in physiological optics, and explores the mechanisms of perception, with a focus on eye movements and the diverse implications of oculomotor research.