All my life I've had bad eyesight. I'm near sighted and few people are lucky enough to be born with good eyes.
I just got a new pair of glasses and shades (prescription) and while the shades are easy to view even with the new lens strength, the glasses however are very discomforting/naseating to use. Both have identical lens presciptions mind you (according to the optometrist).
I discovered the issue with the new frame after reading a poster in my office, 10 feet away from my desk.
Step 1: Curvature!
On my swivel chair I realized the "sweet spot" with my new reading frames is actually DIRECTLY ahead of my eyes. Just small movement up, down or to the side will cause text (on the poster) to become blurry.
My old lens didnt have that problem. Why? It had more curvature. In fact all my previous lenses had curve and the older ones were bigger (oh I miss those).
This Flex On frame has given me tunnel vision now. I have to turn my head to get the best focus.
The lesson: Bigger more curved frames and lens are the best choice for glasses.