Why do onions make our eyes water?

Well, u have lot of scientific explanation, all i want to add that Onion is idea behind invention of TEAR BOMB and if u cut onion while they are dip in water, u will be feeling much better bye

Actually I have no idea, but thank you for raising this question as I would also like to find it out.

...The pigment in the skin of onions is called anthothioxin (sp?, it's been a long time) and it is what makes your eyes water. It is an enzimatic reaction that creates volatile fumes. ...There are ways to slow it down. Try putting the onions you are going to use in the freezer for a few minutes before cutting them. Cut the root end off first. And try breathing through your mouth while cutting them. These hints will not eliminate the fumes, just make them easier to deal with. ...Never cover the onions while you are cooling them. The volatile fumes will leave a bitter residue. It is better to let the steam escape. ...Good cooking. Peace be with you. =(^;^)= Della

i don't do any reaserch on this,and i don't know why.i like onions very much,and everytime i chop onions,i was forced into tears.and i learned a small tip that if you drop some water on onions before you chop it,it won't make you feel terrible.

I have seen in one cooking show that onions emit certain type of chemicals which I think is phosphorus. Our eyes are very sensitive organs and any irritants will cause our lacrimal glands to secret water in the form of tears to cleanse the eyes. To solve the problem the next time you see your husband cooking and before he skins the onions, get a stick (or maybe 2 or 3) of unlighted match then put it between his mouth. The red end should be pointing towards the onions. Matches are made of phosphorus and it will attract the phosphorus emitted by the onions. I don't know if it really works 'coz we seldom use matches nowadays besides it looks funny:-)