I would no more venture out on the bike without my (helmet &) glasses than I would weld without goggles. Not that I weld.
It only takes one bee in the eye at 60 km/h to drive the point home.
As I need prescription, I use Bolle Paroles w/ the prescription insert. I had the prescription made up as bifocal, w/ the reading section made up to a measurement from my eye to the handlebars (computers & route sheet/map), which I took to the optometrist who tested my eyes at that distance. The main part of the lens is my usual "distance" prescription.
The double lens can fog up (like any glasses) and is a bit of a pain when you stop in very humid conditions. They clear as soon as you get moving. I always wear a cap under my helmet, so the brim helps.
BTW, it is very important to shield your eyes from UV ... even if you don't weld. Ask the sheep of New Zealand and Patagonia.