From the American Academy of Ophthalmology:
An Eye M.D. is an ophthalmologist – a medical doctor who provides the full spectrum of eye and vision care. From eyeglasses to contact lenses, to medication and surgery, your Eye M.D. will help you keep your sight for life.
The American Academy of Ophthalmology describes the difference in training between ophthalmologists and optometrists, as well as other eye care providers on their web site.