It turns out that the incidence of myopia... is strongly related to the amount of time that kids spend outdoors ... The more time they spend outdoors, the less nearsightedness they have.

If you get up in the middle the night and go to the bathroom and turn on bright fluorescent light, your melatonin level is slammed to the floor.

A dog sees the world kind of like a particular kind of colorblind human might see the world ... Instead of having three channels to compare and contrast, they only have two channels. And that makes it much more difficult to figure out exactly which wavelength you're looking at.