The eye’s light-sensing retina taps different circuits depending on whether it is generating image-forming vision or carrying out a non-vision function such as regulating pupil size or sleep/wake cycles, according to a new mouse study from the National Eye Institute (NEI) and the National Institute of Mental Health (NIMH). Published in Cell Reports, the findings could have implications for understanding how our eyes help regulate mood, digestion, sleep, and metabolism. NEI and NIMH are part of the National Institutes of Health.