During intern year you do everything but the eye. This year can be spent on the internal medicine service or general surgery service. Usually it's a very busy year where you learn how to be a better clinician.
During residency you learn ophthalmology where you do nothing but the eye (i.e. no more chest pain, strokes, GI bleeds, COPD exacerbation, ICU, etc).
An unrestricted license allows you to practice BY LAW. However, if all you do is an internship year and get your unrestricted license you will only really be able to practice basic primary care medicine -- this used to be called a "GP." The other problem will be you will have a heck of a time trying to get malpractice insurance or be allowed to admit patients to a hospital. Hence why it's so important these days to do a full residency and become board-certified.
In the first 2 years of medical school we only learn the basics of the eye (anatomy, histology, physiology, etc). You're right, after that we don't learn jack until we get to ophtho residency. So someone with just a MD/DO and an intern year under their belt is by no means ready to see eye patients.
However, during residency we have a steep learning curve. We see A TON of pathology, attend lectures and have to study for our annual in-service exam (OKAPs). All that plus seeing emergencies in the ER and doing consults in the hospital. So by the end of your 1st year of ophtho residency (depending on your program and the work ethic of the individual) one should be able to do basic eye exams, general CL fittings and refractions.
I'm actually quite OCD with my exams even if they're there for just glasses.
Pardon my ignorance but what is this considerable liability you speak of? I was under the impression that optometry/ophthalmology are low risk specialities esp if you're non-surgical.
