Why do onions net our eyes break up?

what ingredient in them cause watery and red eyes?Why do onions net our eyes break up?
sulfur compounds are surrounded by onions and when you slice them you release them and they make you adjectives teary and watery red eyes.
Hi:
Well to give a hand me when I need to chop an onion I put it contained by the freezer for 15-20 minutes before chopping it and that seem to reduce the tears seriously.
But to get to you cross-examine it is NOT the juice or odor of the onion that make us cry it is the gasses that are found naturally contained by the onion itself.
I did find an article with an contained by dept explaination and the WHY?
http://www.howstuffworks.com/question539...
Be safe and be okay
See what happens when you cut them the onions release an sour in the heavens thus causing you to slash up every time you go to cut them.Like what you do to counte to be exact wear googles or something like that.
if you go off the bottom of the onion on cut and peel around it you will definately not cry or enjoy red eyes. it is the gases contained by the onion but they only flow when the bottom of the onion is cut rotten
DEAR MISS
BECAUSE THE ONIONS IS REALLY TOO STRONG AND
IF YOU ARE NOT USE TO CUTTING THEM UP THEN
YOUR EYES WILL WATER OK
TAKE CARE