Dr. Egill Hansen (M.D. and Ph.D) is an ophthalmologist and former chief physician of the Ophthalmological Department at the National Hospital in Oslo, Norway. He has extensive clinical experience examining and guiding color blind patients and has taught color vision and its defects for numerous years. Dr. Hansen's international research spans color vision, perimetry, and electrophysiology, and he has also conducted extensive research on diseases causing serious visual damage and blindness.