Subject: I have seen a lot of bad prescriptions.
Item: Some are correct, some are excessive by -1 to -2 diopters. But I (you) never know until you check yourself.
Here are some simple checks you should do for yourself - if you are working to pass the REQUIRED DMV, ro 20/40 line (both eyes open).
http://frauenfeldclinic.com/focal-calculator/calc.htmlJust fill in the requested data. But always check your "cm" distance first. Thus if I have a -2 diopter, "prescription", and my "just blur point" is at 50 cm (20 inches), then the two items match.
I would also included personal Snellen checking, because that is the FINAL test of success.
As always, I consider Dr. Alex's work to be excellent. But success will always depend on what YOU DO - and no one can predict results on what you decide to do (or not do).