this post was submitted on 24 Apr 2026
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Today I Learned

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this is moreso an observation I made while googling around and I don't really have a reason but here's what an article had to say:

Interestingly, large felines like tigers and lions do not have slit-shaped pupils but round-shaped. The reason for this is not exactly defined, but it is thought to be due to their greater height off the ground, their behavior as active foragers rather than ambush predators, or differences in their circadian rhythms compared to cats.
https://www.catster.com/lifestyle/why-do-cats-have-slit-pupils/

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[–] IdolCuriosity@lemmy.world 1 points 1 day ago

Also, small cats tend to have pointy ears, but big cats tend to have rounder ears.

[–] FinjaminPoach@lemmy.world 56 points 1 week ago (1 children)

Labelling the Flash Reflection is really funny to me. It's sort of like finding Saddam Hussein in places he shouldn't be or a diagram of a cat brain which just shows smaller cats in a control room.

Image is from article linked in OP's post

[–] Eheran@lemmy.world 20 points 1 week ago (2 children)

No, it make sense, not everyone realizes that it is actually an artefact and not part of the eye.

[–] forrgott@lemmy.zip 37 points 1 week ago (1 children)

And a good thing they drew it in, then labeled it as irrelevant, too! Can you imagine how confusing the diagram would be otherwise!?

[–] Klear@quokk.au 9 points 1 week ago (1 children)

It's there because it's visible on a lot of cat photos.

[–] Dozzi92@lemmy.world 16 points 1 week ago

It's visible on human photos too, but when I go to my doctor's office the diagram of the human eye doesn't have it. That is a really strange thing to include in the diagram. I like it though, strange is good.

But now I wonder what the lighter green stuff in the bottom third of the eye is supposed to represent.

[–] krigo666@lemmy.world 27 points 1 week ago (2 children)

Pallas's cats (manul) seems to be an anomaly then, they are about the size of the domestic cat and also doesn't have slit pupils.

[–] homes@piefed.world 34 points 1 week ago (1 children)

In fact, they are the only ones that don’t. They are so old, they existed before the slit eye evolved in small cats!

[–] SippyCup@lemmy.world 9 points 1 week ago (1 children)

Ok. First of all, that's a cool ass looking cat. I'd never heard of them before and that has brought some joy to my already pretty joyful morning.

Second of all, you'd think that were there some pressure to do so, they would have evolved similar features if it was an advantage due to their size yeah? It's gotta be an environmental thing or some combination of the two. The slit eyes tend to blur the sides of your vision but bring things directly in your line of sight in to more clarity.

[–] lath@piefed.social 4 points 1 week ago

So, better to hunt small things with?

[–] stoly@lemmy.world 14 points 1 week ago

The slits are an adaptation for hunting in the grass. Large cats stand above the grass and so have eyes more like ours.

[–] BromSwolligans@lemmy.world 13 points 1 week ago

I love looking at big cats for this reason. There's something so cute about them having people-ish (or dog-ish, as you please) eyes.

[–] RememberTheApollo_@lemmy.world 11 points 1 week ago

You knew this. Just imagine the tiger with slit pupils and your brain will “wtf”. Same with panthers, lions, snow leopards, mountain lions…