Personally, I really don't like it, I know a lot of SA riders do it and I understand why with our sun, but I don't like the look and I do think it's dangerous. I have ridden with sunglasses at home but I hate the feeling of them, and they can also change the fit of your helmet.
I know my trainers daughter who does Grand Prixes all up and down the east coast always wears them in every grand prix. I think it helps her see better, as her mom, my trainer used to do. I think it is just personal preference, if some people are willing to take the risk. I do agree there is a little bit of danger to it, I do wear sunglasses a fair amount when flatting, but only plastic ones when jumping. I really don’t think it matters, it might just be cultural.
Hello! I’m currently competing in Europe up to 145 level and constantly go to higher level shows and I rarely see riders wear sunnies. I don’t think it’s necessarily disliked cause I see riders wear it for flatting, but when it comes to jumping it can be relatively dangerous. Especially if you fall and glasses shatter in your eyes you know? That’s why I don’t wear them at least