And how do we know that? I mean, that an eye doctor would rather prescribe glasses than not, it's not surprising. The fact that they'd back up their choice by some "scientific" explanation, is only natural.
Let me offer the opposing view in the form of an example: I have been diagnosed with mild miopia (-0.5), and prescribed glasses. I did wear the glasses for a few months but at some point I lost them, and didn't go back for a replacement. Now about 20 years later, I have never again wear glasses or any other correction and I don't need them (I can read the small leters on the vision tests. I would not say that my vision is 100%, but I never need glasses to see the things in the distance). If anything, my vision improved without wearing correction!