Tricky one this - there are many folk that ride with 'normal glasses'.
I don't.... (I carry normal glasses with me on the commute - they don't give the eye protection....)
I had some prescription Bolle's made many (many) years ago (hence mega bucks) and they were great, but got out dated and the prescription no use.
I'd just spent some serious cash on two sets of glasses for every day use (laser eye treatment option cost zone.....but no way)..... had the new prescription....
New Tesco opened....about 10 miles away.... oh great.... and sports glasses... OFFER....Anyway, went with my new prescription and got some specs for £40..... bargain....
Problem..... the optics were weird - gave me a dodgy 'low' position on the road. By luck found it was the 'shades' not the optical insert - that was fine...
Anyway, nearly about to go stomping off (but £40 was cheap) - and happened to pick up some Bolle Safety glasses that I'd been given on a site once.....hmmmm...... blooming heck, the inserts fit.....
So ended up using Bolle safety glasses (i.e. properly tested for UV, impact etc....) great.....
I currently use the inserts with Bolle Contour and Silium Safety Specs - minor mods to the frames/inserts - job's a good un. If the specs get scratched, it's cheap...
If doing it properly, I'd really opt for Rudy Project's system..... Personally I spend a fair bit on my every day specs, 'cos I need them, the cycling stuff will just have to do.