Costco Optomitrist is the best.
It's no small tasks to get my prescription correct, but Rick Robinson at Costco Sheridan seems to have done it. He uses an automatic system where the change in lenses switches via machine so the distance in time between option 1 or 2 is so fast, your eye can tell the difference. Compare this to the older models of manual switching lenses and the distance in time being a second or two. Costco have invested in a state of the art machine that makes all the difference when it comes to getting your prescription correct. Well done Dr. Robinson.
But, that's just the tip of the iceberg. I moved from Chicago where I overpaid on a prescription refill on existing frames and the Chicago office could not correct the problem. Costco corrected the prescription and gave me new frames and the same lenses for a 1/3 of the cost. I'm saddened at the $1,000's of dollars I've dished out over the years to boutique eye wear shops who overstate their importance in the eye-wear market. I should have listened to friends about Costco optical. I live and learn. Please learn from my mistakes, not your own.