I e-mailed RiDE mag as they had reviewed it and said how good it was, this is the reply:-

Hello.
Thanks for the question. Don't worry. I've used three different Hyper
Optiks on three different lids in the last five years and five
winters in all weathers, day and night without any problem at all.
The insert turns yellow in dull light and if anything seems to
intensify dull light with no detrimental effects at night at all.
I'm not one given to ridiculous and glowing testimonials but if
someone had to ask me what the best (and best value) product for year
round riders that I'd ever used was, I'd the hyper optik, no question.
And before you ask, no, I'm not sponsored - RiDE doesn't do that sort
of thing, it's almost a sackable offence in our office. They are just
that good.

Steve Rose
Editor
RiDE

Might give it a go and let you all know.