I've got photo-grey lenses plus my flip down sun visor. That combination works for me.
Interesting. If that is working, it means your both your clear visor and flip-down visor are not proving UV protection? Photo-grey/brown lenses typically need a significant amount of UV to darken. This would be concerning to me (because a lack of UV protection in something that tints will cause eye damage, since human pupils will open/widen in less visible light). Although I think I read somewhere that there are some newer types of photo-grey that can darken with visible light?