Rayna Bell, a herpetology expert and curator at the California Academy of Sciences, told Snopes it's true that some frogs have heart-shaped pupils, adding that the photo in question appears to be a ...

Pupil shapes vary widely across the animal kingdom, from the W-shaped pupils of cuttlefish to the bar-like pupils of goats. But why are animal pupils shaped so differently? When you purchase through ...

A domestic cat’s eye narrows to a razor-thin vertical slit in bright sunlight, while a grazing sheep stares out through a wide horizontal bar. These are not cosmetic quirks. A 2015 study in Science ...

It's easy to think of pupils as simple holes that widen in the dark and shrink in the light. But if you look across the animal kingdom, you'll see a variety of pupil shapes: vertical slits in cats and ...