most places that sell glasses do those for free tho. I agree they should be given out and they do in europe, or at least in the two states I lived, but being paid for is not the angle to come at it from
So it's a paid-for thing; I don't feel bad about taking the prescription and buying glasses online. That said, the glasses from the shop last way, way longer than the online ones, so I really just use online for sunglasses or like to get novelty frames for a costume or something.
So you're still getting the information that requires special training or licensing, and you can get the other information yourself if you really want it.
Especially in the context of psychotherapy or when using placebos, this makes a lot of sense.
Having worked in the medical field in the past exploring a DICOM dataset was no challenge, and the end result is I have a rotating 3D-view of my own brain! (Well just blood vessels, but still ..)