Todd - was successful. Why - because he looked at his own Snellen, and wore a plus. I see endless over-prescriptions.
https://www.youtube.com/watch?v=5AxzpOyFQjs&t=287sI finally "gave up" on any OD actually helping me to go from 20/50 to 20/20, (refraction -1.0 diopters to +1/2 diopter).
So here are the test lenses that I use to measure my refraction.
I am at 20/20, not because any OD would help - but because I make my own measurements.
Remember - by doing this - you become an expert. This is not medicine - but self-protecting common scientific sense.
I get my lenses from Zenniopical.com - they are good quality.