Check out these microscopic images of tears. So beautiful!
The lacrimal apparatus works to produce tears that are needed to wet the front of the eye and flush debris from the ocular surface.
Many animals yelp or cry out when they're in pain. But as far as scientists can tell, we humans seem to be the only species that shed tears for emotional reasons. Scientists who study evolution say crying probably conferred some benefit and did something to advance our species — because it's stayed with us. Read more here.
A supporter of the Spanish team cries while watching the World Cup final soccer match, which Spain won 1-0. Crying may have evolved as a signal to those who were in close physical proximity to us, but it also adds a powerful dimension to interpersonal communication:


Women do it 64 times a year, men just 17. Actors and politicians do it on demand. But why does crying happen in the first place? John-Paul Flintoff learns that even scientists are still guessing.