When people move through the world they spend most of their time as active controllers operating on the world and less time as passive observers. However, most psychophysical data related to visual control are collected in the passive observer mode. Conversely, there are specialized domains such as aviation and some automated manufacturing industries, where people spend a proportionately larger amount of time as passive observers and must switch frequently between the active and passive modes. A complete understanding of human performance in active controller and passive observer modes is, therefore, necessary in both basic and applied research domains. In basic vision research, there is a need to generalize appropriately findings gathered from passive observers and in applied research of automated environments, there is a need to address safety, training and efficiency issues related to differing behaviors across the active and passive modes.