Originally Posted by big john

Go to a store or pharmacy where they have those racks of cheap reading glasses and try some different ones. I started with 1.25 and eventually went up to 1.75 just to have around before I got my first prescription glasses.
I can use the 1.75s on the bike now even though they aren't strong enough for reading and my eyes are slightly different from each other. I use 'script glasses for driving and they work great for distance but not so great on the bike when I need to see the ground in front of me.