Are you yawning yet? Thought so ... that we blink because we need to keep our eyes moist. When our eyes are open, the tears that usually covers the surface starts to evaporate, and if our eyes ...

Most of us can feel a yawn coming on. The muscles in our jaw begin to tighten, our nostrils might flare, and our eyes might tear up as our mouths stretch open and we inhale a gust of air.