Goats (and most grazing animals) have rectangular pupils that can rotate to stay parallel to the ground
Goats, sheep, horses, and many other grazing prey animals have horizontal, rectangular pupils that give them a nearly 340-degree field of vision. When a goat lowers its head to graze, its eyes rotate up to 50 degrees in the socket to keep the pupils parallel to the ground — maintaining the wide panoramic view needed to detect approaching predators. The rectangular shape maximises the panoramic field while minimising the need to move the head. Vertical slit pupils (cats, foxes) excel at judging precise distances for ambush predators.
Pupils seem like a fixed anatomical feature — a simple aperture for light. Discovering that they actively rotate during head movement, and that their shape is optimised for specific ecological roles (predator vs. prey), makes eye anatomy feel like a precisely engineered tool.
“Goats have rectangular pupils that rotate up to 50° when they lower their head to graze — keeping a panoramic view of predators at all times. Predator eyes have slits; prey animals have rectangles. 🐐 #OddlyHuman”