Dr Barber took his Ph.D. at the Open University, England, in 1990, on mechanisms of memory and learning, with Professor Steven Rose. As a post-doc with Professor Alan Boulton in Saskatoon, Canada, he studied the dopamine system, cerebral ischemia and neuroprotection. In 1993 he worked with Dr Erich Lieth in the Penn State College of Medicine, Department of Neuroscience and Anatomy, on blood-brain and blood-retina barrier, and later moved to Ophthalmology to work on diabetic retinopathy with Dr Tom Gardner. He became Assistant Professor of Ophthalmology in 1999 and Associate Professor in 2006. He continues to work on neurodegeneration in diabetic retinopathy. His current focus is on how diabetes causes vision loss by impairing neuronal function in the retina.