Ophthalmologists are doctors who are trained and specialized in the medical and surgical care of the eyes. They can be either doctor of medicine (MD) or doctors of osteopathy (DO). They provide total eye care, like vision services (fit eyeglasses or contact lenses), eye exams, medical and surgical care, diagnosis, prevention and treatment of disease, and management of complications from other conditions, like diabetes. Ophthalmologists manage or treat patients of all ages group (from premature infants to the elderly), and with acute or long-term eye conditions. They deal with a different range of conditions, including cataracts, squints, infectious eye diseases, glaucoma, eye injuries, and degenerative conditions resulting from aging.