I have done this twice now and both times it has worked. Next time
you have to chop onions, place your cutting board as close to your
sink as possible yet still having a nice stable work surface. Place a
large pan in the sink closest to you. Turn your hot water on about
1/3 or half. Now chop your onion. The hot running water pulls the
onion vapors towards it and not up in your face. It's worked for me!
I have only used the yellow onions, but I would think it should work
with all onions. I recommend putting the pan in the sink to catch the
water so you can use it to rinse off your dishes and not waste the
water! Be "Froogle" here! ) I just thought I'd share this
information with you all!