I bought some zenni sunnies.. wasn't impressed.
The only standard/normal lens option I got was 'Dark Tint' (in black/brown etc).
It didn't say anywhere that Dark = 80% tint.
You have to click 'details' in the shopping cart to see it's 80%.
anyway I found them to be way too dark.. unusable except in really bright environments.
also, the lenses were small for the frame size.. looked weird.. would allow a lot of oblique light in.
happy with zenni service, they gave me store credit (- shipping) and said I didn't need to return the item.
There is a very light gray fashion tint.. but it doesn't give a %.
I'm sure they used to offer choices of tint grades.
I gave the feedback to zenni.. just putting it out here as well.
Thanks for the update.