system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What's the advantage of different pupils in the eyes of different creatures? I.e. Cats having slit pupil, where as ours are circular.
gpt
A lot of it is a byproduct of evolution. The theory is that nocturnal animals have slit pupils so if they have move around in the daytime they won't burn out their eyes from the sun since slit pupils can block out most of the light.

We don't really have many answers apart from that. Grazing animals also have large pupils, presumably for better peripheral vision. Big cats, like lions and tigers, have round pupils like we do as well, the theory being that their vision is higher up from the ground because they're bigger. Slit pupils are linked to small predators apparently.

The most valid and true answer at this point in time is: evolution is weird.

Did a few minutes of research on this, scientists can only speculate.