Recent research has identified neurons in the visual system that remap their receptive fields before a saccade. The activity of these neurons may signal a prediction of postsaccadic visual input, derived from an efference copy of saccadic motor output. Such a prediction is often thought to underlie our perception of a stable visual world, by compensating for the shifts in retinal image that accompany each eye movement. Here we review the evidence, and conclude that prediction does not in fact...