While it has been said that the eyes are a window to the soul, a new study shows they could be a means for understanding diseases of the brain. According to new research by scientists at the UCSF Weill Institute for Neurosciences, retinal scans can detect key changes in blood vessels that may provide an early sign of Alzheimer’s disease, while offering important insights into how one of the most common Alzheimer’s risk genes contributes to the disease.