Vision Monocular

do sea stars have monocular vision?

My daughter is doing a project for school, and we read an article that said sea stars have a kind of ‘eye’ at the end of each arm. Is that true, and would that mean it has monocular vision? We have spent days researching and even went to a zoo, but still don’t have an answer! Thanks!

Sea stars do not have “vision” as most people think of it: they do not have a brain, and nothing remotely like a visual cortex. Their eyespots do little more than allow the animal to tell the difference between light and dark. I could not find any sources concerning any additional processing of the information from the various eyespots.

Edit:
I found a paper that talks about an experiment with two species of sea urchin (sea urchins and sea stars are both echinoderms) that suggests that they have a limited sort of “spatial vision”. Essentially, it says that the collection of eyespots over the body of an echinoderm act as a single, very crude, compound eye. I would imagine that it would be like viewing the world through one eye covered with several layers of frosted glass. So, in a sense, sea stars MAY have an extremely crude sort of monocular vision.

Edit:
I found another paper about experiments with brittle stars that suggests that their eyespots can discern between polarized and non-polarized light, which MAY allow them to tell when they are in shallow water.

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