In 1979, James Gibson completed his third and final book "The Ecological Approach to Visual Perception". That book can be seen as the synthesis of the many radical ideas he proposed over the previous 30 years - the concept of information and its sufficiency, the necessary link between perception and action, the need to see perception in relation to an animal's particular ecological niche and the meanings (affordances) offered by the visual world. One of the fundamental concepts that lies beyond all of Gibson's thinking is that of optic flow: the constantly changing patterns of light that reach our eyes and the information it provides. My purpose in writing this paper has been to evaluate the legacy of Gibson's conceptual ideas and to consider how his ideas have influenced and changed the way we study perception.