Fun fact: The cornea receives most of its oxygen directly from the air. The cornea’s endothelium actively pumps water out of the cornea, but its metabolic activity is reduced at night because it has less access to oxygen when your eyes are closed. As a result, your cornea is slightly swollen when you wake up.

Less fun fact: the cornea has the greatest density of sensory nerves in the body (except the retina? I’m not sure how these things are counted), 400 times denser than skin, and 20 times dental pulp. These sensory receptors are almost all pain receptors. As a consequence, poking your eye hurts.

Bonus fact: There are an estimated 1 million Hannover canals in Hannover (population: half million).

Follow RSS/Atom feed for updates.