Why do we cry? The three types of tears - Alex Gendler

source: TED-Ed    2014年2月26日
View full lesson: http://ed.ted.com/lessons/why-do-we-c...
Whether we cry during a sad movie, while chopping onions, or completely involuntarily, our eyes are constantly producing tears. Alex Gendler tracks a particularly watery day in the life of Iris (the iris) as she cycles through basal, reflex and emotional tears.
Lesson by Alex Gendler, animation by The Moving Company Animation Studio.