Use this thread to tell people about nice little things that most people probably don't know about.

When you look up at the sky on a clear blue day you may notice that you can see lots of fickle white 'sparks' buzzing along. These are actually your white blood cells moving through the capillaries in your eye. It's known as the blue field entroptic effect.

http://en.wikipedia.org/wiki/Blue_field_entoptic_phenomenon