3 ms·
It's been my understanding since I started getting glasses in the 8th grade in the in the United States that Optometrists have an OD (a non-medical doctorate),
by tingletech 7y ago
It's been my understanding since I started getting glasses in the 8th grade in the in the United States that Optometrists have an OD (a non-medical doctorate), Ophthalmologists have an MD from a medical school (with the full rights thereof, such as prescribing medicine), and Opticians are the technicians who fit and order your prescription.
That same Optometrist who taught me that also taught me about diopters (the inverse of the focal length in meters squared) and optics of my negative prescription.