I hear that chewing gum actually helps with the eyes watering.
Also, I refrigerate them before I cut them. That helps a lot. My eyes can still water, but not as much as it would if I didn't put them in the fridge.
You can also try the following:
1) Cut the onion under a vent (as long as you have a pretty good vent)r
2) Soak it in water for a little bit (just make sure you cut off the ends and peel it before you do soak it. Soak it for 15 minutes)
3) Wear goggles (you may look ridiculous, but c'mon.....no tears
)
4) Freeze it (put it in the freezer for 15 minutes before you cut it)