This paper represents Graeme's main PhD project. Graeme was interested in how stereo vision copes with the changing epipolar geometry caused by eye movements. By cleverly manipulating the geometry of the viewed stimuli, Graeme showed that stereo correspondence does not take account of changes in vertical disparity which occur as our eyes move from viewing near to far objects, but remains optimised for far viewing. I think this is a unique situation where a pattern of vertical disparity produces no depth percept on its own, but enhances the visibility of depth due to horizontal disparity.