Why Do Onions Remove Water From The Eyes?

 

Onions are an essential ingredient in many dishes and have been a part of human diets for thousands of years. Despite their popularity, onions have one annoying side effect: they make our eyes water.

This phenomenon has puzzled people for a long time, and scientists have been trying to unravel the mystery behind it. In this article, we’ll explore why onions make our eyes water and what causes this reaction.

What causes onion-induced tears?

The compound responsible for making us cry while cutting onions is called syn-propanethial-S-oxide. This compound is released when onions are cut, sliced, or chopped, and it irritates the eyes, causing them to water.

When syn-propanethial-S-oxide is released, it reacts with the natural moisture in the eyes, forming a mild acid. This acid irritates the eyes, which triggers the production of tears.

Why do onions produce syn-propanediol-S-oxide?

Onions produce syn-propanediol-S-oxide as a defense mechanism against animals that might try to eat them. This compound is released when the onion is damaged, either by being cut, chewed, or crushed.

The release of syn-propanethial-S-oxide is the onion’s way of deterring animals from eating it, as the compound can cause a burning sensation in the mouth and eyes.

How to prevent onion-induced tears?

There are several ways to prevent onion-induced tears. One popular method is to freeze the onion before cutting it. Freezing the onion before cutting it slows down the release of syn-propanediol-S-oxide, reducing the amount of the compound that irritates the eyes.

Another way to prevent tears is to cut the onion under running water. The water washes away the syn-propanethial-S-oxide before it has a chance to react with the natural moisture in the eyes.

Why do some people not cry while cutting onions?

It’s not uncommon for some people not to cry while cutting onions. This is because the ability to cry while cutting onions is genetic.

Some people have a genetic variation that prevents them from producing tears in response to syn-propanethial-S-oxide. However, it’s important to note that even if you don’t produce tears while cutting onions, the compound can still irritate your eyes and cause discomfort.

Can onions be harmful to the eyes?

While onions can cause discomfort and irritation, they are not harmful to the eyes. The tears produced when cutting onions are simply the body’s way of flushing out the irritant.

However, it’s important to note that if you wear contact lenses, cutting onions can cause discomfort and irritation, and you should take extra precautions to protect your eyes.