Researchers have discovered the reason that different animals have different-shaped pupils. And it's all got to do with food.
Researchers led by Professor Martin Banks have found a strong correlation between pupil shape and an animal's ecological niche—where and how they find food and when they do so.
According to the study, published in the journal Science Advances, vertical pupils suggest predator while horizontal pupils suggest prey.
The scientists studied the eyes of 214 vertebrates and found small predators who ambush their prey tend to have pupils that narrow vertically—which helps to increase focus and depth perception. Prey animals tend to have pupils that narrow horizontally—creating a panoramic view which helps to detect and evade a
