Ophthalmology, medical specialty dealing with the diagnosis and treatment of diseases and disorders of the eye. The first ophthalmologists were oculists. These paramedical specialists practiced on an itinerant basis during the Middle Ages. Georg Bartisch, a German physician who wrote on eye diseases in the 16th century, is sometimes credited with founding the medical practice of ophthalmology.
The function of the human eye is to receive visual images. Whatever adversely affects vision is the concern of the ophthalmologist, whether it be caused by faulty development of the eye, disease, injury, degeneration, senescence, or refraction. He makes tests of visual function and examines the interior of the eye as part of a general physical examination for symptoms of systemic or neurologic diseases. He prescribes medical treatment for eye disease and glasses for refraction and performs surgical operations where indicated.