Russell Foster is a world leading neuroscientist at the University of Oxford. In both ophthalmology and psychiatry his innovative research in sleep and circadian biology is having a major impact upon clinical practice: His findings have transformed our understanding of how the eye works and Foster’s collaboration with ophthalmologists is redefining the assessment, treatment and care of individuals with eye disease. Many of the health problems that arise from disturbed sleep are also found in mental illness, but these problems are rarely linked back to sleep abnormalities. Foster has developed the hypothesis that mental illness and many forms of sleep disruption are linked by common pathways, and that an understanding of these shared mechanisms will provide key insights into normal brain function.