While riding in the low 30 degree weather late this afternoon with
lots of wind, I needed the protection of my best balaclava, the
neoprene one that mostly covers my nose and mouth. Its downside is
that it funnels lots of moist air to my glasses, which promptly fog
up. Since I was on a dedicated bike path, I just put away my glasses,
but my eyesight isn't good enough to do that on roads.

So, any solutions?

I'm considering ski goggles, of which Smith makes one over the glasses
model with a battery-powered "Turbo Fan" intended to minimize fogging,
(http://smithsport.com/products/snowgoggle/turbocam_knowledgeturbo.html)
but wonder if anyone has actually tried such a solution for winter
biking, or if there might be better alternative ideas.