Spatial Vision, Vol. 21, No. 6, pp. 509– 529 (2008)  Koninklijke Brill NV, Leiden, 2008. Also available online - www.brill.nl/sv Vision with one eye: a review of visual function following unilateral enucleation JENNIFER K. E. STEEVES 1,2,3,4,* , ESTHER G. GONZÁLEZ 1,3,4,5 and MARTIN J. STEINBACH 1,2,3,4,5 1 Centre for Vision Research, York University, Toronto, Canada 2 Department of Psychology, York University, Toronto, Canada 3 Department of Ophthalmology and Vision Sciences, University of Toronto, Canada 4 The Hospital for Sick Children, Toronto, Canada 5 Vision Science Research Program, Toronto Western Hospital, Toronto, Canada Received 23 April 2007; accepted 14 June 2007 Abstract—What happens to vision in the remaining eye following the loss of vision in the fellow eye? Does the one-eyed individual have supernormal visual ability with the remaining eye in order to adapt and compensate for the loss of binocularity and the binocular depth cue, stereopsis? There are subtle changes in visual function following the complete loss of one eye from unilateral enucleation. Losing binocularity early in life results in a dissociation in form perception and motion processing: some aspects of visual spatial ability are enhanced, whereas motion processing and oculomotor behaviour appear to be adversely affected suggesting they are intrinsically linked to the presence of binocularity in early life. These differential effects may be due to a number of factors, including plasticity through recruitment of resources to the remaining eye; the absence of binocular inhibitory interactions; and/or years of monocular practice after enucleation. Finally, despite this dissociation of spatial vision and motion processing, research that has examined visual direction and performance on monocular tasks shows adaptive effects as a result of the loss of one eye. Practically speaking, one-eyed individuals maintain perfectly normal lives and are not limited by their lack of binocularity. Keywords: Enucleation; monocular deprivation; spatial vision; motion processing; visual direction. INTRODUCTION It is a popular belief that losing the ability to use one sensory system results in a ‘sharpening’ of the other remaining senses. For example, the typical layperson might hold the belief that a person who is completely blind will have more acute hearing than someone with full vision. This is an empirical question — are blind * To whom correspondence should be addressed. E-mail: steeves@yorku.ca