This year my allergies have been pretty bad, despite actually taking medication for it(I usually tough it out until I can't stand it or my sinuses are infected but I finally concluded I wasn't going to build up a tolerance to whatever pollen bothers me). I have found that even glasses aren't really enough and so when I go out on the road, I will drip a few drops of water from my bottle into my eyes and its enough to flush some of the pollen out and give me an hour's relief. I imagine if you've got to be out every day and no other solution presents itself, buy a bottle of eyedrops and use at will.
In the woods two days ago the air was thick with pollen as though I'd blown the dust off a tomb. My sunglasses helped a bit but it was also getting dark and I was losing track of the trail. Some days you just can't win.