Have you ever noticed how animals have different shaped eyes like how some cats can have round pupils and some can have “cat eyes” or vertical diamond eyes? An animal’s pupils can be based off of how they get their food. Depending on what an animal eats as well as how easily they can get their food, that will depend on how well they can see far out or close up. And depending on their vision, that will depend on what the shape their pupils are whether that is round pupils or vertical slits.
Animals that have a more of the vertical slits are more likely to be ambush predators that are diurnal (active during the day and the night). An animal with round pupils are known as active foragers that will chase down their prey. These animals will have both of their eyes in the front of their heads.
UC Berkeley Study
In a study done by UC Berkeley, there was a total of 214 species of land animals studied. Out of those 214 species, there was a total 65 frontal-eyed ambush predators. Out of these 65 animals, 44 had vertical slits. 36 of those 44 were smaller animals less than 17 inches tall at the shoulder. According to this study, vertical pupils are found to maximize the ability of smaller animals to judge the distance of their prey while larger predators tend to have round pupils.
Looking at the pictures below, you will notice in the left picture, there are 3 crosses at different distances. The camera is focused on the first cross which makes it clear and sharp. All the other vertical lines are also pretty sharp compared to the blurred horizontal lines. This is a good example of how vertical pupiled animals can see vertical objects a lot better than horizontal objects. The other photo on the right shows what an animal with vertical slits will see based on their vision. It also shows the blurred ratio to the object that they are focused on.
Domestic vs. Big Cats
Now the cat species can be just a bit different! A lot of people, when they see or imagine a domesticated house cat, imagine a cat with so called “cat eyes” or “snake eyes,” those vertical slits. While this is true with domesticated house cats, they don’t just have vertical slit pupils, their pupils change to round when needed. This all depends on light and their emotion. With a house cat that is more content and relaxed, their pupils will be vertical slits. When the cat is excited or about to pounce, their pupils will become round and larger.
Lions and tigers are different than domestic house cats, having round pupils instead of vertical slits. This is again due to size and diet. So next time you are hanging out with your cat, maybe pay attention to those eyes a little closer. This might tell you if your cat is relaxed or excited. Then, head on over to TCWR to see if you can gander at some of those big cat eyes to see the difference!
Sources
https://news.berkeley.edu/2015/08/07/pupil-shape-and-ecological-niche/