Name from west to east the four Great Lakes shared by Canada and the US Lake Superior, Lake Huron, Lake Erie, Lake Ontario Name the Great Lake that lies entirely in the boundaries of the US.
Definition of ophthalmology for English Language Learners. medical : the study of the structure, functions, and diseases of the eye.
An ophthalmologist is a physician (doctor of medicine, MD, or doctor of osteopathy, DO) who specializes in the medical and surgical care of the eyes and visual system and in the prevention of eye disease and injury.