Well I do have the same thing occur with the sun hitting the headlight bucket and triple t reflecting back the rays. It can be a pain in the butt, but wouldn't change a thing. Just divert my eye, or move the helmet slightly to not have it blind me. That and wearing some type of sun glasses or tinted lens doesn't hurt either.
I guess if I was taking a long trip where I had to run directly into the sun for awhile, maybe stick some masking tape such as the blue stuff that comes off clean and easy over it. When I have those situation in the past though, I usually had a bar bag on the front which did block the rays also.