To the best of my knowledge, no you cannot. This is because visors are made to certain standard, and cutting a hole in them means they no longer meet that standard.
hi , i've recently brought a g force helmet with the built in fresh air fitting , got that from racer imports , camron keeps then in stock , they work great , and seal up from dust good as well.
__________________
were we're goin we dont need roads.
it's not the speed of life that scares me, it's the sudden stop at the end ,