Why Do People Cry Only When They Cut Onions, Not Other Vegetables?

Have you ever wondered why onions make you cry when you cut them, but not other vegetables? Let’s find out:

Onions have a defence mechanism to protect themselves from various animals that feed on roots, tubers, and bulbs.

When you cut onions, their skin is broken and it emits enzymes and sulfenic acid, which combine and become propanethial S-oxide.

When this gas touches the protective water layer on our eyeballs, it turns to sulfuric acid.

Our eyes produce tears to flush out the irritant as a defence mechanism to protect the eyes from harm. The reaction may be more intense for people who are allergic to onions.