An ophthalmologist is a physician who specializes in the medical and surgical care of the eyes and visual system and in the prevention of eye disease and injury. They provide a full spectrum of care including routine eye exams, diagnosis and medical treatment of eye disorders and diseases, prescriptions for eyeglasses, surgery, and management of eye problems that are caused by systemic illnesses. Ophthalmologists can be medical doctors (MD) or doctors of osteopathy (DO).