Other than getting waterproof glasses, there is not much that can be done. You can get a little bottle of anti fog that is used for ski-goggles or scuba gear. I am sure that many scope dealers have something similar.....but most of them seem to be mostly alcohol. You can buy your own alcohol a lot cheaper. A little bit of dishsoap mixed with water works also. Just apply a little and then polish it dry with either product.
I just try to keep mine as dry as possible, and I do not put my eyes up close to the lenses, but rather, I just put the tips of the glasses against my eyebrows and look through, then put them back inside my jacket.
I have been thinking of trying the Bushnell Elite glasses with rainguard because My rainguard scope works excellent.