Sight is our dominant sense modality in the acquisition of environmental knowledge. Cultural, personal and academic contexts, however, mean that the relationship between sight and knowledge is reciprocal and ambivalent in nature. A wide variety of examples illustrate how knowledge both widens and narrows vision. Mode of explanation and ordering of knowledge, though embedded in previous conceptions, rely heavily on insight and current perception. We live in a visual world. Our environment consists of outward and visible expressions of our culture, in the transmission of which the visual has always played a prime role, be it building, ritual, dress--or blackboard. Moreover, for the most recent generations the advent of television has dramatically widened the eye of immediate comprehension. While psychologists debate its influence as an electronic child-minder and entertainer, its power is recognized and sought by advertiser and politician alike. The written word has therefore undergone revaluation. Steiner has written generally on the retreat of literary culture,1 which, ironically enough, has occurred during a period of exponential growth in the amount of material published. The devaluation of textual expression or argument, epitomized in tabloid, or 'popular' newspapers, may occasionally be discerned among weightier publications. One recent venture, for instance, a ten-volume encyclopaedia, demoted the written text to only two of its volumes, the bulk forming a 'colourpaedia' of illustrations.2 Geography is to such an extent a visual discipline that, uniquely among the social sciences, sight is almost certainly a prerequisite for its pursuit.3 Visual aids characterize its classroom teaching, while outside field observation and inculcation of an eye for country are essential complementary requisites. Geographers therefore are--or should be--strongly interested in the nature of seeing, and in the consequent ramifications of such findings for their exercise of describing and understanding man-environment relationships. Certainly the advance of radical and humanistic approaches in general, and of perception and image studies in particular, have reawakened recent interest. The aim of the present essay is to reflect on various aspects of the relationship between sight-including insight, foresight, even hindsight-and the acquisition, evaluation and ordering of environmental knowledge.