Thank you for this insight! I am highly motivated to get Rx sunglasses this year. I wear the progressive multi-focal lens in my distance glasses (versus my computer lens glasses; so happy I got those), and was wondering if the effect those have (where you have to be mostly squared up with what needs to be in focus through the middle of the lens and stuff left and right is not in focus) would be worsened with a wrap around sunglasses lens. My doctor mentioned going with a bifocal lens in the sunglasses over the progressive, and that makes sense given your explanation. I'm looking forward to having a pair for fishing.