First important point - cheap!
Second point - I've got large head, which does affect choices a bit...
At the moment I've got some DHB yellow glasses which I wear for most day-time rides but they're starting to get a bit scratched up and loose. And I've got some old clear safety glasses nicked from my last employer for night-riding.
I'd like to replace them both with a set with replacable yellow and clear lenses. I find its never bright enough in the UK to need dark lenses, especially if you're in and out of shade in woodland etc.
Any suggestions gratefuly received!
http://www.amazon.co.uk/Bolle-Spider-Safety-Glasses-Mirror/dp/B000MGSK36
i have had 2 pairs of these,1st pair got run over by a landrover,i picked them up,bent them back into shape and they done me the whole days riding with minimal damage,i cant imagine a pair of oakleys doing this...
*Edit,just noticed the mention of changable lenses,try Lidl.i got a pair for 6quid with 3 lenses and hard carry case,plus a bunge type cord to put on instead of the legs,
Have a look at the fake jawbones on deal extreme, if they're still doing them
cheers.
Had a look through DX (tempted by some daft thin goggles) and ended up on ebay, found a few sets which look good value.