What is the difference between an optometrist and an ophthalmologist?

Physician or not: An ophthalmologist is a physician (M.D. Or D.O.) who specializes in treating diseases of the eye. They can do all the same basic stuff as an optometrist but can also prescribe drugs (like any doc) and perform surgery, etc. They go to med school just like family docs and pediatricians. Optometrists go to a different school to learn their craft and perform eye exams and prescribe lenses.

Medical school: Optometrists go to optometry school and some have "residencies" but the confusion probably comes from terms like dr and optometric physician. Ophthalmologists go to medical school, residency, and possibly fellowship and the main differences right now have to do with surgical training / experience by the time of graduation but there is a constant battle over scope of practice.

Eye docs: Optometrists are trained to fit lenses and have a smattering of knowledge of eye disease. They have legislative privileges to do more than their qualifications. An ophthalmologists is to an optometrist as a lawyer is to a legal assistant. Ophthalmologists are mds, take a board exam and are continually retested. Optoms have no board, no retesting, cannot do surgery, etc. Big difference.