I was thinking about this today on my ride in at 23 F degrees . The wind was almost a dead calm at 3 mph and I was thinking how much more uncomfortable it might be with strong winds across my face and body. when I dress, I do look at the predicted wind speed, but not to the point where I plan on the wind-chill being the temperature to dress for. riding in 15-20 mph wind (regardless of direction) would have changed the experience. I was a little over-dressed today but my eyes were comfortable uncovered. if it were a windy day I would have probably missed the eyewear.