Do you know why tears start flowing from your eyes automatically when you cut onions (Why Do Onions Make You Cry) as if an emotional scene of a film is going on? If not, then this article is for you. This is the magic of a small chemical process hidden inside the onion. Let us explain its science to you in simple words in this article.

Highlights

1. While cutting onions, people's eyes often start tearing up.
2. When onion is cut, it releases a gas which causes irritation in the eyes.
3. This irritation forces the eyes to shed tears, which is a 'self-defense' reaction.

Tears flowing from the eyes while cutting onions is so common that most people have considered it a part of the kitchen, but have you ever wondered why this happens (Why Do Onions Make You Cry)? Does onion want to make us cry or is there any scientific reason behind it? Let us explain this interesting fact of science to you in simple language.

Onion and its self defense

Actually, onion uses a special chemical 'self-defense' to protect itself from animals and insects. When we cut onions, we are damaging its cells. Now, since there are some special enzymes hidden inside these cells, which become active immediately when the onion is cut.

This is why tears come

As soon as we cut the onion, these enzymes and sulfur enzymes come in contact with each other. Due to this chemical process, a gas is formed, which easily dissolves in the air, which is called Syn-propanethial S-oxide in scientific language. Let us tell you, this is the main culprit that causes irritation in our eyes .

Access to eyes and reaction

This gas spreads in the air and reaches our eyes. Let us tell you, there is a thin liquid layer in our eyes, which is called tear film. When syn-propanethial S-oxide gas comes in contact with this tear film, it dissolves in it and turns into a mildly irritating enzyme like sulfuric acid.

defense system of the eyes

Our eyes are very sensitive , so when they sense any kind of irritation or danger, they immediately activate their defense system. In this situation, the tear glands of the eyes start producing tears in large quantities.

The purpose of these tears is to flush out any irritating substance that enters the eyes, just like a particle of dust enters the eye. So, the next time you start crying while chopping onions, know that this is your eyes' natural way of protecting themselves.