Goats, like most hoofed mammals, have horizontal pupils. The
purpose of those elongated pupils is to allow them to scan the
horizon for possible predators. When a goat’s head tilts up (to
look around) and down (to munch on grass), an amazing thing
happens. The eyeballs actually rotate clockwise or
counterclockwise within the eye socket. This keeps the pupils
oriented to the horizontal. That seems impossible to believe.
Eyeballs might be able to scan from side to side, or swivel up
and down, but how could they actually rotate clockwise or
counterclockwise? To test out this theory, I took photos of
Lucky the goat’s head in two different positions, down and up. I
then tilted one of the photos so that the slope of his forehead
(marked by arrows) was constant. The photos prove that the
pupils actually swivel about 25 degrees within the head.