Why do our eyes tear when we cut onions? This is a common question that often puzzles people. Cutting onions is a simple task, yet it can lead to tears almost instantly. The answer lies in the science behind our eyes and the chemicals released by onions.
Onions contain a chemical called syn-Propanethial-S-oxide, which is released when they are cut or chopped. This chemical is a potent irritant to the eyes. When we cut onions, the syn-Propanethial-S-oxide is released into the air and quickly travels to our eyes. The tears that result are our body’s natural defense mechanism to wash away the irritant and protect the eyes.
Our eyes are equipped with a complex system of glands that produce tears. These tears serve multiple purposes, including keeping the eyes moist, washing away foreign particles, and providing a protective layer against infection. When the syn-Propanethial-S-oxide comes into contact with the tear film on our eyes, it triggers a reflex that causes tears to be produced in larger quantities.
This reflex is known as the lacrimal reflex, and it is designed to protect our eyes from harmful substances. The tears produced during this reflex are called reflex tears, and they are different from the tears we produce when we are emotionally upset. Reflex tears are clear and watery, and their primary function is to flush out irritants from the eyes.
While the lacrimal reflex is a natural and protective response, it can be quite uncomfortable. To minimize the tears when cutting onions, there are a few strategies you can try. First, cutting onions under running water can help to disperse the syn-Propanethial-S-oxide and reduce its concentration in the air. Second, using a sharp knife can help to minimize the amount of onion that is cut, thereby reducing the amount of syn-Propanethial-S-oxide released. Lastly, wearing protective goggles can prevent the syn-Propanethial-S-oxide from reaching your eyes altogether.
Understanding why our eyes tear when we cut onions can help us appreciate the intricate workings of our body’s defense system. It also gives us practical tips to minimize the discomfort during this common kitchen task. The next time you find yourself tearing up while slicing onions, remember that it’s just your body’s way of keeping your eyes safe and healthy.
