This chapter reviews a large body of work that has demonstrated the cross-modal involvement of visual cortical areas in non-visual tasks, both in the sighted and in the blind. According to common belief, blindness is associated with superior non-visual perception. Rats deprived of vision at birth are able to navigate a maze for a food reward faster than normal, and also show altered somatosensory receptive fields in the whisker barrel representation in somatosensory cortex. Paralleling the changes in performance and somatosensory cortex, neonatal visual deprivation in rats results in the appearance of somatosensory responsiveness in the anterior parts of occipital cortex, as shown by both electrophysiology and autoradiography. The effects of blindness on non-visual perceptual abilities and on cerebral cortical function might be attributed to long-term neural plasticity. However, the same cannot apply to similar changes noted, amazingly, after short-term visual deprivation of normally sighted subjects.