Sleep can facilitate memory formation, but its role in cortical plasticity is poorly understood. A recent study found that sleep, following monocular deprivation (MD), facilitated cortical changes in ocular dominance. The magnitude of plasticity was similar to that observed after continued MD, and larger than that seen after sleep deprivation in darkness, suggesting that sleep per se enables mechanisms of cortical plasticity. Experience-dependent plasticity during sleep could be part of a more global process of memory consolidation.