I think the persimmon lenses are pretty dark for night riding... they block about 50% of the light if I recall. I've used them and it was OK with two headlights that were theoretically 1600 lumens each (cough) but anything outside the headlight pool was dark as a tootsie roll. Not ideal. They work great for rides that start at dawn or dusk and take you into full daylight - 50% is tolerable when it's bright out.
Tifosi makes a photochromatic lens that goes from 25%-75%, I think I'm going to try that out if I can find a set that fit my large head.