Here’s why cats eyes have creepy vertical slits for pupils
A new research has revealed facts about how to recognize whether your kitten is a prey or predator. Scientists say that ambush predators have pupils who are vertical slits.
"For species that are active both night and day, like domestic cats, slit pupils provide the dynamic range needed to help them see in dim light yet not get blinded by the midday sun", said lead researcher Martin Banks, professor of optometry at University of California-Berkeley.
Compared to humans' circular pupils that undergo a mere 15-fold change, the vertical slits of domestic cats and geckos undergo a 135 and 300-fold change in area between constricted and dilated states, said the researchers who conducted the study.
On the other hand, species that have horizontally elongated pupils appear to be the plant-eating prey species. Their eyes are on the sides of their heads.
Active foragers or animals that satiate their hunger by chasing and feeding on their prey have circular pupils. To measure distance, animals rely on binocular disparity, motion parallax and blur.
Binocular disparity and blur work in tandem with vertically elongated pupils and front-facing eyes. Both cues are maximized by vertical-slit pupils. Ambush predators do not have vertical pupils equally distributed.
William Sprague, a postdoctoral researcher in Banks' lab, said they were surprised to know that slit pupils were linked to predators that were close to the ground. The researchers say unlike bigger cats, like tigers and lions, domestic cats have vertical slits.