Onions make us cry because they release tiny air bubbles that irritate our eyes.
When you chop an onion, you’re cutting through its layers. Inside each layer are little cells, and those cells have tiny air bubbles in them. When the cells get broken by the knife, the air bubbles come out. These bubbles carry a chemical called tears gas, which is like a tiny invisible spray.
Your eyes feel this tears gas, and they try to wash it away by making you cry. It’s like when you get sand in your eye, your eyes blink fast to get rid of the sand, and sometimes they even cry!
Why it feels so strong
The tears gas is very strong, especially if you chop a lot of onions. Your eyes might feel like they're being tickled by an invisible bug! But don’t worry, once you stop chopping, your eyes will calm down, and the crying will stop too.
Examples
- A child cutting an onion for the first time and suddenly crying
- Someone chopping an onion in a kitchen without any eye protection
- A beginner chef trying to make a salad but ending up with tears
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See also
- Why do onions make you cry when you cut them?
- What is Lacrimation (tearing)?
- Why Do Humans Have an 'Ugly Cry'?
- What are reflex tears?
- Are humans the only species who drink milk as adults?