Vision is obviously important for the control of goal-directed locomotion. This profound influence can be best revealed by interfering with the visual pathways or by altering the visual inputs normally expected to occur during locomotion. For instance, the use of reversed optic flow or reversing prisms can induce significant locomotor changes or lead to powerful illusions, such as the sensation of backward walking while actually walking forward. To better understand the many ways by which visual inputs could actually influence locomotion, an overview of some of the background concepts on the generation, initiation, and control of locomotion is given and, when pertinent, mechanisms by which vision could interact with locomotion at different control levels of the central nervous system are postulated.