My solution for fogging up a fullface helmet was to cut a drinking straw into two 3-4 inch bits and exhale out the bottom of the helmet. no more foggy visor or glasses.
For my radbike I use cheap clip on sunglasses on my prescription glasses with a fleece balaclava. the wind while riding is enough to keep fog off the lenses, just uncover your nose at stoplights.
For my radbike I use cheap clip on sunglasses on my prescription glasses with a fleece balaclava. the wind while riding is enough to keep fog off the lenses, just uncover your nose at stoplights.