I picked up one of these Hyper Optik inserts that mount on the inside your visor and are light sensitive to darken when in bright sunlight. The other weekend we rode over Loveland pass after beginning the morning in Morrison. There was a pretty big temperature drop as we rode up, which was probably the cause of the adhesive on the insert letting go and causing the insert to bounce around on my nose as I tried to keep up w/ the pack.
I contacted FogCity (Modern World) and spoke w/ one of the guys there who was cool enough to take the time and replace the insert directly for me. Once I got the insert mounted securely on the visor I have been happy w/ how it works and would rate it as being about the same effectiveness as my yellow tinted riding glasses. I'd recommend one for anyone who is tired of carrying both tinted/clear lenses w/ them or doesn't like to wear sunglasses inside the helmet.