It’s annoying, isn’t it? Your eyes stream when you slice through those onions. Every time. And as your eyes fill, it’s harder to see, so you slow down, which is worse, because you just want to get it over with.
When you cut through onions, it starts a number of chemical reactions which results in a gas that irritates the eyes.
Syn-propanethial-S-oxide, to be exact.
Why do you cry more than others?
Some people have better tears than others – a better more efficient tear quality. A bit like how some people have a more moisturised skin. So if you have a good quality tear film, it acts as a barrier to prevent much of the gas from reaching the sensitive nerve cells on the front of your eye (the cornea). The more gas that hits the nerve cells, the more likely your eyes will water.
Hormones affect the tear film quality. Be it during pregnancy, menopause, or the natural changes in your monthly cycle. The shift in hormones results in a poorer tear film. And that means less protection against that onion.
How to reduce the tears. Essentially there are 3 ways:
- Improve your tear film
- Use protection
- Your mouth can help
Improve your tear film
There are several ways to improve your tear film – use tear lubricants before slicing, beefs up your tear layer. You can get these over the counter. Sometimes tear gland production can be improved naturally and a bespoke treatment plan can be designed for you – a good optometrist can give you advice. Improving your omega 3 (fish oils) can improve tear quality too.
Adding another barrier between your eyes and the onions will reduce the amount of vapour reaching your eyes. Glasses and contact lenses have been shown to help. But the best option is tight fitting swimming goggles for an all-round seal! And yes, you can buy specific onion goggles online.
Your mouth can help
Breathe through your mouth. This draws the gas over your wet tongue. The olfactory nerves, which are closely located to the tear duct nerves, will be bypassed and there will be no tears generated. This is easily confirmed when you forget and breathe through your nose. Instant tears! So those housewife tips of chewing bread, having a silver spoon in your mouth or sticking your tongue out, do have a sound basis.