Cats have vertical slit pupils that expand dramatically. This helps them judge distance perfectly while hunting, especially in low-light conditions like dusk or dawn. Octopuses have bizarre W-shaped ...

The horizontal axis represents the time elapsed following the presentation of the image, while the vertical axis denotes the degree of change in pupil diameter relative to the image presentation. A ...

I've read that cats have vertical pupils because they are more efficient at sensing the movement of prey, whether in the air or on the ground. Likewise, goats and other biggish herbivores have ...