Why Do Your Eyes Water When Chopping Onions?

If you’ve ever had to chop onions while cooking dinner, you may have experienced a stinging pain in your eyes. The severity of this burning sensation can vary from person to person, ranging in intensity from “mildly annoying” to “unbearably painful.” But why exactly do our eyes water when chopping onions?

When you slice into an onion, you break open thousands of microscopic cells. When these cells are broken into, they release enzymes that turn into volatile gas when they combine with the air. This reaction creates a lachrymatory agent, which is a chemical compound similar to the chemicals included in tear gas. When the gas reaches your eyes, your tear ducts begin watering in an attempt to flush out the gas.

At our banquet hall in Bensalem, we know that there are a few methods that you can use to lessen stinging and pain when chopping onions, including:

  • Using a very sharp knife. Using a very sharp knife to slice your onions releases less gas into the air.
  • Slice the root last. The majority of an onion’s enzymes are contained in its roots. Slice this part up last to limit the burning and stinging.
  • Light a match before you begin peeling and chopping onions. The sulfur in the match disables the airborne compounds that cause the chemical reaction to form. Less gas in the air means less tears.
  • Avoid touching your eyes and face while working. Touching your eyes, nose, or mouth while you’re slicing onions can directly introduce gas into your body, which makes the pain worse. Always avoid touching your face until you’ve had a chance to wash your hands.


Do you have a special event coming up that needs an impressive menu? Village Catering’s custom catering in Philadelphia can be personalized to fit your unique guest list and event. Give us a call today to learn more or make your reservation!