Looking up at the blue sky we actually see our own white blood cells

Staring up at the blue sky we sometimes see white non static spots scattering all about. This is called blue field entoptic phenomenon and Richard Scheerer, a German ophthalmologist , first drew clinical attention to it in 1924.‘Blue field entoptic phenomenon’ or Scheerer’s phenomenon is the appearance of tiny bright short-lived, visible for a second or less dots moving quickly along squiggly lines in the visual field, especially when looking into bright blue light such as the sky.

What are these dots? They are white blood cells moving in the capillaries in front of the retina of the eye!