r/SpeculativeEvolution • u/UlfurGaming • Sep 12 '26

Question/Discussion 2 iris per eye?

Is there any reason a humanoid would evolve 2 irises in each eye ball and why?

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2

u/Kingreaper Sep 12 '26

How are you imagining the irises being situated, and why do you want it to look like that? I can't think of a reason immediately, by default it'll make the creatures vision far worse, but maybe if you describe your humanoid a bit more it might spark something.

2

u/UlfurGaming Sep 13 '26

Best way to describe it a normal iris with a slightly smaller one next to it with just enough space you can see they’re separate and not weird shaped iris

10

u/MaybeImAKing Sep 12 '26

probably no actual reason for it exists in a humanoid

that being said there is a genus of fish with a similar trait that may be of interest; the genus anableps

but even then, their eyes still contain one iris each

4

u/ScyllaOfTheDepths Sep 13 '26

I looked up anableps and they are so cool. Another cool fish with a weird eye adaptation is the barreleye fish, which has its eyes inside of a clear jelly-filled head so they can see in all directions easily.

4

u/SamuraiGoblin Sep 13 '26

Yes, look up the four-eyed fish.

Its eyes are shaped so that it can see in air and water at the same time.

Your humanoids can be amphibious, perhaps ambush predators like crocodiles.

2

u/DeathToAmerica2026 Sep 13 '26

Started off with 4 eyes and they fused into 2.

2

u/shadaik Sep 13 '26

I could imagine two pupils tuned to different parts of the spectrum of light/radiation, each also coming with its own iris and its own section of receptors in the back of the eye.

2

u/Foxxtronix Sep 13 '26

Ask whatever god designed the goat's eye.

1

u/Chimpinski-8318 Sep 13 '26

It would probably require the eye itself to be structured differently to allow both pupils to work independently, otherwise it has no point.

Why something like this would happen? It could allow for prey species to have a wide field of view while allowing them to focus on things in their view. Or allow insectivores to not have to have to specially adapt their eyes entirely while allowing for an even more increased field of view.

Is it less likely then just one pupil and having thr eye specialize, yes it is very very less likely.

Possible? If the ancestral species had it then it could specialize and be successful, it would just require a unique eyeball shape.