<unk>  is the branch of medicine which deals with the diseases and surgery of the visual pathways, including the eye, brain, and areas surrounding the eye, such as the lacrimal system and eyelids. The word<unk>  comes from the Greek roots<unk> hthalmos meaning eye and logos meaning word, thought or discourse;<unk>  literally means "The science of eyes." As a discipline it applies to animal eyes also, since the differences from human practice are surprisingly minor and are related mainly to differences in anatomy or prevalence, not differences in disease processes.  However, veterinary medicine is regulated separately in many countries and states/provinces resulting in few<unk> sts treating both humans and animals.  By convention the term<unk> st is more restricted and implies a medically trained specialist. Since<unk> sts perform<unk> erations on eyes, they are generally categorized as surgeons.
Ophthalmology
Otology
Neuroendocrinology
Diabetology
Rheumatology
Stomatology
Pedodontics
Hematology