I also remember a chemistry professor saying that if you used a stainless steel knife or touched a stainless steel surface when cutting an onion that would keep you from tearing up. I cannot say for sure that this works as he would toss out some really wild things regarding the chemistry of food. I will say I do have a stainless steel knife that I use for cutting onions and I do not shed any tears.
I also remember a chemistry professor saying that if you used a stainless steel knife or touched a stainless steel surface when cutting an onion that would keep you from tearing up. I cannot say for sure that this works as he would toss out some really wild things regarding the chemistry of food. I will say I do have a stainless steel knife that I use for cutting onions and I do not shed any tears.