I wear contacts and sunglasses most of the time when I ski or snow shoe. There's stuff called Cat Cr*p (really) that you can buy at just about any sporting goods store that stops the fogging.

On a side note, why don't you just get reading glasses to wear over your contacts? That way, you don't have to have glasses on all of the time. I have a pair of progressives for the rare times I have my contacts out; I don't necessarily keep the prescription up to date, since I only wear them reading in bed.