1) Rain-X water repellant is said by some bikers to work well.
2) If it doesn't, try this:
   a) Moisten a bar of soap with water and wipe the soapy water on your lenses.
   b) wait for the water to dry in a soapy film on the lens.
   c) Buff the film clear with a lens cloth or soft towel. don't use a paper towel or tissue, it will scratch your lenses. If you do this on both sides, your glasses shouldn't fog - works with ski goggles & eyeglasses.
3) Spit on the lenses, rub, then rinse off. Many people swear by this.