in reply to ur lense fogging you can do one of 2 things (a) make a new lense which is costly and could be problematic. Or you can (b) before you jump take a potato and rub it on the inside of your helmet lense. after you saturate ur lense simply buff clear! i know this because snowmobile racicers use this merthod to prevent fogging on the trail!
hope you find this useful
BLUE SKIES!