Ever wonder why your eyes water when you chop onions?

Ever wonder why your eyes water when you chop onions? 

It's because onions contain sulfur compounds that react with the moisture in your eyes, producing sulfuric acid. Your eyes respond by producing tears to flush out the irritant. 

As for remedies, slicing onions near running water or chilling them beforehand can help reduce the release of these compounds, making the experience less irritating for your eyes.