Not wanting to wear your expensive cycling specific glasses while cycling incase you damage them while cycling is a pretty funny concept.
Thanks for that!

Good quality Photochromic and polarised Oakley copies are available online for about a tenner if you honestly think the styling looks nice and want an option that does exactly the same thing for around 8% of the cost. (some of the really cheap ones aren't all that well styled so unless you know what you're looking for it can be a bit of a lottery)
and... Yes .They're UV protective. All clear plastic is.
Photochromatic still generally shields a small percentage of light so even in dark woods when the lenses "look" clear you'll have slightly reduced light.
as above though something like Decathlon's own brand that are cheap and you can actually try on might be the best option.