Optometrists and Ophthalmologists both have training to check for disease in the eyes. In fact a dilated eye exam is a non-invasive way to get an actual look into your circulatory system to check for things like diabetes. So even people without glasses should be getting regular checkups.

Ophthalmologists also have specialized training for cutting the eye that they learn in medical school (eg: lasik), but for eye exams, an optometrist has the skill-set necessary to perform these kinds of screenings.

A lot of people just get auto-refracted or a checkup by an optician and assume that's enough to get new glasses, but those people can be among the tens of millions of Americans who don't realize they have pre-diabetes.

Is it, though?

My ophtalmologist wouldn't only perform measurements to see if my prescription had changed. She would do a proper eye checkup. Retina, pressure and a host of other things.

It wasn't expensive. Of course, it was also not in the US.

You are only there once a year at most, so it is an opportunity to catch things before they go wrong.

I have had the same experience in the US. An assistant rather than the ophtalmologist is the one that does the vision test (I guess it's called the refraction?). The assistant then dilutes my eyes and after that is when the ophtalmologist comes in to do the checkup for my eyes for issues.