A domestic cat’s eye narrows to a razor-thin vertical slit in bright sunlight, while a grazing sheep stares out through a ...

Hello all, it’s Manasee Wagh, service and news editor at PopMech. Years ago, I had a cat named Cyrus. I used to stare at him staring at me, and wonder what he was thinking. He had beautiful gold-green ...

Pupil shapes vary widely across the animal kingdom, from the W-shaped pupils of cuttlefish to the bar-like pupils of goats.