Russell Foster, Professor of Circadian Neuroscience, studies sleep and its role in our lives, examining how our perception of light influences our sleep-wake rhythms. The research on light perception hits home as we age — faced with fading vision, we also risk disrupted sleep cycles, which have very serious consequences, including lack of concentration, depression and cognitive decline. The more we learn about how our eyes and bodies create our sleep cycles, the more seriously we can begin to take sleep as a therapy.