Home / AMERICAN NEWS / Why Do Animals’ Pupils Have Different Shapes? — ‘The Why’

Why Do Animals’ Pupils Have Different Shapes? — ‘The Why’

Welcome to the newest edition of The Why.Why do animals’ pupils have different shapes?” Good question. (OK, it’s a little odd but again it beats answering those questions about some of your more personal peccadilloes. We thought a “Fur Ball” was just something that cats coughed up, mmmkay?)


Ophelia/Image: Phoenix

So why do animals’ pupils have different shapes? According to a study published Friday in the journal Science Advances, reports the results of the study of 214 species. It indicates that animals’ pupils have different shapes because it gives them “a survival edge.”

Our guest speaker Nicholas St. Fleur contributor to The New York Times online also reported on the study and confirms this. He states: “Vertical pupils and circular pupils help certain predators hunt, while horizontal pupils help other species spot predators from afar. . . (according to) “a team of scientists from the University of California, Berkeley, and Durham University in Britain.”

He adds that they “used computer models” to support their “theories about why horizontal, vertical and circular pupil shapes benefit different animals. When the model’s pupil was horizontal, more light could be captured from the left and right of the eye . . . and less light from below and above the eye. This would allow grazing animals to better detect predators approaching from different directions.”


Fatbot Angus/Image: Phoenix

The researchers also utilized a computer model to learn the advantages of vertical slit eyes. St. Fleur confirms that the team discovered “that vertical pupils help an ambush predator better estimate the distance to its prey by sharpening depth perception and its focus on a target.” They also believe that “large predators such as tigers and lions that ambush prey have circular pupils . . . “because these animals are taller, their eyes do not have to compensate as much for those visual cues.”

While critics point out there are “exceptions to the rules” this new study still provides us with more of an intelligent answer than we have had previously. (Besides, it is also said that it is the exception that proves the rule, right? Can you really get a doctorate and never have heard that?)


Ophelia/Image: Phoenix

Jenny Read, a vision scientist at Newcastle University in Britain, concluded that this research could strengthen the argument that animals’ pupils have different shapes because “evolution and natural selection have optimized the eyes over millions of years.”

Why do animals’ pupils have different shapes? Now you know.

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About Will Phoenix

W. Scott Phoenix, B.A., B.S. was born in Hawaii, raised in Pennsylvania and resides in California. He has been a published writer since 1978. His work has appeared (under various names) in numerous places in print and online including Examiner.com. He is a single parent of three children and has also worked as an actor, singer and teacher. He has been employed by such publications as the Daily Collegian and the Los Angeles Times.