Hysterical blindness is a thing

I saw it twice in 10 years of working for neurologists. I haven't seen it once in 35 years of optometry.

just because you can't measure something (yet) doesn't mean it isn't real science

Blaming stress for myopia is like blaming fairies when you lose your keys.

depression is also hard to measure but no one disputes its existence.

Depression can be measured by counting symptoms. Stress can be measured by counting symptoms, sorta. But if you're blaming stress for physiological vision loss or structural myopia, your research project will get some laughs but no funding.

Placebo and nocebo have recognized effects on ciliary tonus in young people. That doesn't mean it has anything to do with anatomical progressive myopia or other pathological loss of vision.