Why do onions release compounds that make us cry?

Onions make us cry because they release tiny chemical messengers when we cut them.

Imagine you're playing a game where every time you touch something, it sends out little helpers to tell your eyes what's going on. When you slice an onion, it’s like the onion is shouting for help, and those helpers are called sulfur compounds. They float up into the air and land in our eyes.

Our eyes get a tiny bit irritated by these sulfur compounds, just like when something spicy gets on your face. To wash it away, our eyes start making more tears, which is why we end up crying!

It’s kind of like when you’re eating hot chocolate and it burns your tongue, your body sends water to help cool it down. In the same way, your eyes send out tears to clean up the mess from the onion.

So next time you see an onion, think of it as a little tear-maker that’s trying to protect itself, and maybe you’ll laugh instead of cry!