Sleep is an urgent topic for neuroscientists and now more than ever is known about its crucial importance for concentration and memory formation. Despite all this, the western world spends fewer and fewer hours asleep. With human interaction increasingly taking place in timeless virtual spaces, our time spent asleep is shortening and our working days are lengthening, with profound implications for the quality of the lives we lead. In particular, the impact of light-emitting screens upon the circadian rhythms, so essential to well-being, are only just becoming apparent.