Why do onions make you cry and how do you stop it?

Onions are basically tiny, spicy defense mechanisms^[3]. When you slice into them, you break their cell walls, mixing compounds that create a noxious gas called allyl sulfide^[3][4]. This gas hits your eyes and turns into a form of sulfuric acid, forcing your tear glands to go into overdrive to flush it out^[4][5].

To stop the waterworks, try these hacks: chill the onion in the freezer for 15 minutes to slow down the enzyme release^[5], use a super sharp knife to minimize cell damage^[4], or just wear swimming goggles for a total seal^[3][5]. You can also set up a small fan to blow those vapors away from your face^[3][4].