Why do our eyes water, when we cut Onions?

It's caused by an enzyme called lachrymatory-factor synthase. Don't ask me how to pronounce the first part of that enzyme.A reaction occurs that releases this thing called syn-propanethial-S-oxide, which triggers thetears by contacting nerve fibers on the cornea that activates the tear gland. Did you know that scientists have tried to make a non-crying onion? I didn't. But they can't because the chemical that makes you cry, gives the onion the flavor it has.

Chopping onion makes us cry bcoz it has cells produce enzymes that are released when the onion is chopped and the cells break open. These enzymes create a gas, which reacts with the moisture in your eyes to produce a mild sulfuric acid. The acid irritates the eyes, producing tears.

I can't really explain why it happens but if you run cold water from you sink while cutting onions your don't seem to water. I works for me.

Maybe it is because of the curse of the onions.

Maybe it is because of the curse of the onions.

I think that it's because the smell irritates our eyes.

maybe the smell is just to much for them so the let it out.

even i too don't know the reason...ya but if u put the onions in cold water and then cut then your eyes do not get tears.

but dem in water n den try choping dem...u wont cry dat much!:)