If you live in New York and have ventured outdoors over the past few days, you have experienced the bitter cold and freezing winds of the polar vertex. It's quite likely you've also experienced tearing from yours eyes when the wind gusted against your face. Kelly Ripa and anchor-people in almost every morning show have been crying this morning: "why are our eyes tearing?!"
The tearing we experience in winter-time when we step outside, is caused by excessive dryness on the surface of the eye -- the cornea. Counter-intuitive isn't it, that tearing is an indication of dryness? The ambient humidity on cold days is near zero percent, and the evaporative loss of the tear film by cold gusts further increase the dryness on the corneal surface. The corneal nerves sense this dryness and send a message to our tear glands to release tears. These tears are not part of the baseline tear secretion that takes place throughtout the day. Rather, they are reflex tears that re-wet our eyes in their time of need.
Watch the video above to gleen more about the different types of tears our body produces and the basic tear film components. And stay warm out there!