My vision is still doing the slow slide into old age, but I juggle 4 different lenses in 3 frames. The driving/close-reading bifocals don't change very often. (I can put up with a fair amount of "the freeway signs are a bit fuzzy" before I come anywhere near needing to update for safety reasons.) But I spend most of my waking life staring at computers and need different glasses for the desktop monitors and the home laptop. I go in to my optometrist with a carefully measured "required focal distance" for each pair. Generally I'll update them both when the desktop monitor glasses start giving me headaches.