Brittle starfish are second known example of vision in an organism without eyes | Hacker News Reader

Brittle starfish are second known example of vision in an organism without eyes

cell.com

72 pointsbookofjoe20 comments

>Only one species of sea urchin has ‘passed’ the same tests for vision, and it also, independently, changes color in response to light levels. Future work will probe whether this sea urchin, the only other animal in the world known to see without eyes, might be using a similar trick to Ophiocoma.

Source: https://scitechdaily.com/scientists-just-showed-that-color-c...

The term they use to describe this phenomena is "extraocular vision". Defined as the ability to see without eyes.

More info: https://aspirantworld.in/extraocular-vision/

Couldn't you say that any plant that orients itself towards the sun (e.g. sunflower) can detect light without eyes?

You could argue photosynthesis is a crude form of vision.

Indeed, it seems like a pretty subtle distinction. Given sufficiently bright light, sunflowers would certainly pass the behavioral experiment done here (which is very nicely summarized in Figure 1 of the paper).

The distinction must be in the ability of these starfish to resolve objects (with an angular resolution between 30-50 degrees apparently).

Sensing light is distinguished from seeing in the first sentence of the abstract:

>>Almost all animals can sense light, but only those with spatial vision can ‘‘see.’’

This amazing type of sensory perception reminded me of another animal w/ a star shaped apparatus https://en.m.wikipedia.org/wiki/Star-nosed_mole.

My favorite quote from the Wikipedia entry, "evolution has repeatedly come to the same solution for constructing a high-acuity sensory system: subdivide the sensory surface into a large, lower-resolution periphery for scanning a wide range of stimuli, and a small, high-resolution area that can be focused on objects of importance" -Vanderbilt University neuroscientist Kenneth Catania

Cuttlefish probably have some sort of vision on their skin; they are able to make camouflage which matches the color of their environment, but their eyes only have black and white vision. Note, this is still evolving science, see https://www.sciencemag.org/news/2016/07/how-colorblind-cuttl... for one explanation.

I have a (fairly stupid) question after reading this...

Is the human brain hard-coded for vision through eyes or is it possible to a (at least similar) form of vision without eyes, or like a much less exaggerated form of sonar like Daredevil, is the human brain REALLY that adaptable?

In an attempt to restore vision to those that lost it, is their a way to mentally rehab someone to "see" in a different way?

People who cannot see often turn to echolocation: https://www.sciencemag.org/news/2019/10/echolocation-blind-p...

Very much so. Besides adaptation like Human Echolocation (https://en.wikipedia.org/wiki/Human_echolocation), there is also active research for devices to help. Look at https://en.wikipedia.org/wiki/Sensory_substitution#Tactile%E... for example, and there are videos of the various devices in use by blind people, eg. https://www.youtube.com/watch?v=7s1VAVcM8s8

I read about a blind guy who had a camera hooked up to an array of electrodes on his back and eventually was able to 'see' using it. That was a long time ago, but it looks like it's still a thing nowadays, see 'Brainport' [1] and 'Visual Prosthesis' [2] (aka 'bionic eye'). It's amazing how plastic brains and nervous systems seem to be!

[1] https://www.scientificamerican.com/article/device-lets-blind...

[2] https://en.m.wikipedia.org/wiki/Visual_prosthesis

That’s amazing and actually reminds me of a book I read about young Merlin. As a child Merlin was blinded but learned to “see” by sensing objects with magic. Eventually he became so good at it that even though he didn’t use his eyes, it was just as good as normal sight.

This episode of the 20,000 Hz podcast talks about blind gamers able to play Killer Instint solely by listening to the audio. Players gave input to Microsoft on how they could make the game even more accessible by tweaking the audio cues, and Microsoft patched the game in response. Amazing.

https://www.20k.org/episodes/levelup about 16 minutes in.

Microsoft has been doing some great things for accessibility in gaming. Whether it’s because the CEO has a profoundly disabled son or unrelated, it is great for so many disabled people for whom gaming is a deliciously escapist experience.

This should be tagged as PDF.

Although HN can't really do anything about it, it's also worth noting the PDF linked is named "mmc3.pdf", which greatly confused me for a moment because I happened to also have the MMC-3 spec[1] opened in my PDF reader, and it's also roughly the same size.

[1] http://www.13thmonkey.org/documentation/SCSI/mmc3r10g.pdf

I suppose it depends on what you consider "eyes" -- these starfish could be said to have many effectively single-pixel "eyes" instead of two high-resolution ones.

Eye is fairly well defined in biology. Think of it as the difference between 'light sensor' and 'camera'. A fully-formed eye will incorporate some form of lens.

> Echinoderms form the focus of extraocular vision research

Very droll.

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