One more addition to my previous comments :

A piece of bread held in the mouth does nothing.

Cutting the onions near an open flame does create convection, pulling SOME of the fumes away but not nearly enough to avoid the watery eyes.

Goggles can work, but they can also hinder your sight and peripheral vision, increasing your risk of injury.

Trying to cut the onions under water is impractical and dangerous. The fumes are only blocked as long as the onion pieces are submerged in the water the minute they're sliced, they float to the surface, releasing the gas.

Plus, trying to cut and hold the onions underwater greatly increases the likelihood of accidentally cutting yourself, because the onions will constantly slip and slide and fight their way out of your hands and to the surface of the water.

As I said, the only proven way to avoid the tears is to chill the onions thoroughly in the freezer or crisper drawer first.

THEN once their chilled, cut or chop the onions in small batches at a time (so that you'll be able to get them done and put away before they come to room temperature, avoiding the fumes and tears.

For me it's still goggles, otherwise - tears.

I'm not sure if this tip has been posted in the past, but I found it today:

If you're going to cut onions then make sure you a) have good ventilation, b) soak them in water, and c) use a sharp knife.

I've tried the candle burning trick, the wearing goggles trick, etc but I found the three methods to cutting onions without crying were pretty simple. I would peel off the brown outside (the part that's attached to the stem of the onion) to where all you have is the yellow/white/red outer layer. I then cut the onion in half, toss it into some water, and let them soak for about 30 minutes. After that, I put the onion on the cutting board and made sure I used a sharp knife. If you use a dull knife, it'll tear the skin that holds the odor cells that makes the onions stink and spray juice everywhere.

I read this whole scientific reasoning behind what causes people to cry when cutting an onion but I couldn't find it again.

Great tip!!! wish I knew it years ago.

Cutting onions is something I do for a living. Some days I have to slice up about 50 pounds for onion rings. Other days I only have to do 5-10 pounds.

Cold onions are less smelly yes.
Running under water does help.
Make sure the onions are very fresh. The older the onion the more it smells.
Breathe through your mouth not your nose while cutting onions.
If you get too teared up go stick your head in a fridge.... at work I walk into the freezer or cooler and breathe deep through your mouth to clear the onion stuff.

If you have to cut up large amounts of onions you might peel them all and ask a local restaurant if they would put them through their Hobart slicer/copper.

For those freezing onions a question. Do you blanch them first or do you just bag them and freeze them? I want to start freezing veggies like peppers and onions and have not really done it before.

Its an excellent tip.

Neat - useful tips for me as I find onions very hard to endure

Thanks for all these tips! I found them really useful!