Ophthalmology (/ˌɒfθɑːlˈmɑːlədʒi/ or /ˌɒpθɑːlˈmɒlədʒi/) is the branch of medicine that deals with the anatomy, physiology and diseases of the eyeball. An ophthalmologist is a specialist in medical and surgical eye problems. Since ophthalmologists perform operations on eyes, they are both surgical and medical specialists. A multitude of diseases and conditions can be diagnosed from the eye
The Greek roots of the word ophthalmology are ὀφθαλμός (ophthalmos, “eye”) and -λoγία (-logia, “study, discourse”), i.e., “the study of eyes”. The discipline applies to all animal eyes, whether human or not, since the practice and procedures are quite similar with respect to disease processes, while differences in anatomy or disease prevalence, whether subtle or substantial, may differentiate the two