This arrangement actually optimizes color vision in the daytime and night vision at night. Evolution selected for the correct arrangement for those of us living on land:
YOU HAVE NO POWER HERE
Submitted 5 weeks ago by fossilesque@mander.xyz to science_memes@mander.xyz
https://mander.xyz/pictrs/image/217bc085-d052-46bf-87d9-ce172d6e4b81.jpeg
Comments
canihasaccount@lemmy.world 5 weeks ago
bigpEE@lemmy.world 5 weeks ago
This is just saying that the glial cells help make this less bad than it could be, no? Nothing about why neurons behind receptors would be worse
canihasaccount@lemmy.world 5 weeks ago
No, glia support neurons; they do things like redirecting blood flow to more-active-than-usual neurons, mylenate axons, etc. They wouldn’t form a mesh around neurons’ photoreceptors the same way they do neurons’ somas and axons. What the article describes is that glia actually are critical at allowing for color vision during the day and night vision at night, since on land we’d get too much blue light to see color with much fidelity were it not for glia, and a similar filtration process helps us see at night. It’s not that it’s not as bad as it could be, it’s actually that vision is better this way (barring one small blind spot outside of our fovea–which, being outside of the fovea, would have low acuity anyways).
diverging@piefed.social 5 weeks ago
Because of this we have blind spots, one for each eye. They are not usually noticeable because 1) the blind spot of one eye can be seen by the other, and 2) the brain fills in the gap.
So with this I will perform a magic trick, I will make your thumb disappear: Close your left eye and with your right look at a spot in the background, make a thumbs up gesture and place the tip of your thumb on that spot, move your thumb to the the right continuing to look at the spot in the background, when your thumb moves about 15 cm your thumb should disappear.
You can use you left eye too, just switch the directions.
InvalidName2@lemmy.zip 5 weeks ago
It’s way too late at night for all those directions, somehow ended up creating my own blind spot by sticking my thumb in my bum.
diverging@piefed.social 5 weeks ago
Well, I guess your thumb disappeared.
I can try another way the blind spot is about 15 cm at arms length to the right of the right eyes center of vision. So put your thumb there and it should disappear
tacosanonymous@mander.xyz 5 weeks ago
At least your dick didn’t get stuck in the toaster.
drmoose@lemmy.world 5 weeks ago
the brain fills in the gap
To expand on this, current leading theory (predictive processing) says that brain first generates a visual image than confirms it with inputs and if there’s no input to confirm/deny the halucination it’s just accepted as is. So we can have a whole load of blind spots in all of our sensors and continue functioning rather well with an ocassional artifact.
Whats_your_reasoning@lemmy.world 5 weeks ago
I think about this at night when my eyes are forced to attempt to make sense of the low light levels in a dark room. I know my room isn’t grainy and grey-scale - that’s just the best my eyes and brain can do at night. It’s interesting to look around and try to imagine the proper colors and shapes of things, reckoning the difference between what I know and what I see in the moment.
With our brains constantly making things up to explain gaps in information, it’s no wonder kids think they see “monsters” in the dark. It’s also no wonder that nightlights work well to keep said “monsters” away.
BuboScandiacus@mander.xyz 5 weeks ago
AI witchhunting crowd hates this one simple trick !
Carrot@lemmy.today 5 weeks ago
Woah, i didn’t know that the effect would be so drastic. I want to point out to those struggling to get it to work that, as diverging mentioned, your arm needs to be fully extended. Also, the blind spot is about a thumb’s width, at least for me, and is only visible at a specific x/y axis location. Any deviation from that single spot will cause it to stop working. I could tell I was close to the spot when parts of my thumb would disappear, and just had to slowly move it around until I found the spot that looked like the thumb was gone completely.
0ops@piefed.zip 5 weeks ago
Thanks you helped me see it (or not see it I guess)
Modern_medicine_isnt@lemmy.world 5 weeks ago
I couldn’t make it work. But I did notice that the spot in the background changed focus a tiny bit at one point. I suspect my brain was tracking the thumb and simply refused to continue to truely focus on the background spot. I tried and tried, but just couldn’t make it happen. Neither eye. :(
Catoblepas@piefed.blahaj.zone 5 weeks ago
Make sure to hold it at arm’s length, if you weren’t already. If it’s close to you it’s too big to vanish into the blind spot.
callyral@pawb.social 5 weeks ago
It looks like there’s just a gap in spacetime or something.
By the way, your eyes are not meant to track your thumb when doing this, you have to keep still and move only your thumb for it to work, so don’t move your eyes.
Eq0@literature.cafe 5 weeks ago
Succeeded, thanks! That’s uncanny!
clot27@lemmy.zip 5 weeks ago
What is a “spot in the background”? Like where exactly
Todd_cross@lemmy.dbzer0.com 5 weeks ago
Anywhere. It makes it easier, if you have a dot or a feature to look at, but really it’s anywhere in the distance.
Thedogdrinkscoffee@lemmy.ca 5 weeks ago
More mindflayer propaganda.
luciole@beehaw.org 5 weeks ago
ph’nglui mglw’nafh Cthulhu R’lyeh wgah’nagl fhtagn and so on
gedaliyah@lemmy.world 5 weeks ago
✅ Discount number of limbs
✅ Cheaply made eyeballs
✅ Held together with a bunch of inflexible bones
Wait, am I just an off-band octopus?
Damn.
Goun@lemmy.ml 5 weeks ago
- just one brain
rumba@lemmy.zip 5 weeks ago
I wonder if that afforded some level of protection to the surface dwellers’ receptors when in direct contact with high levels of sunlight.
IndustryStandard@lemmy.world 5 weeks ago
As usual with biologists, if they don’t understand what it does they claim it’s a useless byproduct of evolution. A few years later they discover there is actual purpose to it and it’s actually pretty nifty. Rinse and repeat.
darkangelazuarl@lemmy.world 5 weeks ago
I have heard the theory that it evolved this way for higher UV protection that was not needed in underwater organisms. Curious if it was really that much of a competitive advantage though.
rumba@lemmy.zip 5 weeks ago
See this comment:
cheers, thanks for that!
Pyr_Pressure@lemmy.ca 5 weeks ago
Wonder what would happen if an octopus looked directly at the sun
rumba@lemmy.zip 5 weeks ago
Or an oarfish or anything from the midnight zone that actually has eyes
ArmchairAce1944@discuss.online 5 weeks ago
I am biology illiterate. Explanation please.
Hugin@lemmy.world 5 weeks ago
Cephalopod precursors evolved eyes and then brains developed from the eye so their eye is structured correctly.
Vertebrate precursors evolved the brian first and the eye evolved out the brain as a sensory stub. So it’s upside down and inside out like in picture.
The nerve cluster goes through the back of the eye splits and folds back to end in light receptors. Light hase to go through the nerves before hitting the sensor.
There is even a reflective layer after the sensors that gives the sensors a second chance at picking up the light. This is what causes the red eye or green eye you sometimes see in flash photography.
It would require a genetic rebuild to fix this and the intermediate steps evolution usually use would be so disadvantageous they are selected against. So the right combo of mutations to give us a working octopus eye is VERY unlikely to happen.
ArmchairAce1944@discuss.online 5 weeks ago
Hypothetically, if we managed to make a genetically modified human with the eye that you are talking about, what advantages/disadvantages would it have over our current eyes?
Tattorack@lemmy.world 5 weeks ago
Hypothetically, what would be the advantages of “correcting” this evolutionary mistake in humans?
prole@lemmy.blahaj.zone 5 weeks ago
Is this at all related to why the part of the brain that does visual processioning is way in the back?
CaptainBlagbird@lemmy.world 5 weeks ago
Octopuses don’t have a dead spot in the eyes I guess
fossilesque@mander.xyz 5 weeks ago
Scallops, oysters, mussels and clams have anywhere between 40 and 200 eyes. en.wikipedia.org/wiki/Mollusc_eye
Tollana1234567@lemmy.today 5 weeks ago
convergently evolved eyes, cephalod pod eyes evolved very differently from tetrapods. cephalpod eyes evolved by forming an invagination of those tissues. whereas the tetrapods evolved as extensions of thier brain.
socsa@piefed.social 5 weeks ago
Having a larger focal point farther back from the aperture should also reduce parallax, I crease field of view and improve depth perception.
melsaskca@lemmy.ca 5 weeks ago
Shit just evolves. It doesn’t evolve correctly or incorrectly.
squaresinger@lemmy.world 5 weeks ago
Evolution likes local maxima. Getting out of them is difficult. That’s what the OOP meant with “evolution was powerless to correct it”.
Getting out of local maxima means you first have to go with a worse setup until you get to a new, better local maxima. That’s why evolution doesn’t really do that all that often and instead prefers small optimizations.
(I use “like” and “prefer” not to say that evolution has goals or emotions, but to say that that’s what the “algorithm” of evolution leads to.)
Nangijala@feddit.dk 5 weeks ago
That explains the platypus.
Or as an old classmate told me in college: the platypus is proof that nature has a sense of humor.
TheTechnician27@lemmy.world 5 weeks ago
en.wikipedia.org/wiki/Cephalopod_eye
(At a glance, this article needs some touching up and hasn’t been meaningfully contributed to in some years.)
Rachelhazideas@lemmy.world 5 weeks ago
Quick way to find your blindspot:
- Close your right eye
- Hold your phone/monitor 1ft (30cm) away from your face
- Look at the ‘x’ below
- Slowly bring your phone towards you (or your face towards the monitor) until the ‘.’ disappears
. x
BuboScandiacus@mander.xyz 5 weeks ago
faythofdragons@slrpnk.net 5 weeks ago
Your username says you’re an owl, but you’re suspiciously squid shaped
EldenLord@lemmy.world 5 weeks ago
God I love Splatoon character design
jsomae@lemmy.ml 5 weeks ago
The
.is not visible to me at any distance.Jax@sh.itjust.works 5 weeks ago
The ‘.’ never disappears???
Rachelhazideas@lemmy.world 5 weeks ago
Make sure to keep your left eye looking at the ‘x’ the whole time. The ‘.’ should only be in your peripheral vision.
someguy3@lemmy.world 5 weeks ago
Whats_your_reasoning@lemmy.world 5 weeks ago
Lol, at first glance I thought this was a poster for some new movie. All we need to do is change the font of “Cephalopods” to something exciting, and arrange the listed species as if they were actors’ names.
MonkderVierte@lemmy.zip 5 weeks ago
Not sure if all but at least 7. and 8. are extinct.
SubArcticTundra@lemmy.ml 5 weeks ago
Do I understand correctly that our ancestors had left the water before this upgrade dropped for fish?
diverging@piefed.social 5 weeks ago
I don't think you understand correctly. The cephalopod eye and the fish eye (which includes tetrapods) evolved independently.
Bishma@discuss.tchncs.de 5 weeks ago
This is the meme that set off Cylon Number One (aka John Cavil) and eventually lead to the attack on the 12 colonies.
betanumerus@lemmy.ca 5 weeks ago
If vertebrae don’t have it, it means they don’t need it.
NounsAndWords@lemmy.world 5 weeks ago
I’ve said it for years, as soon as it’s commercially available I’m getting photoreceptors realignment surgery.
errer@lemmy.world 5 weeks ago
Is this something we could like, fix?
Typhoon@lemmy.ca 5 weeks ago
This is one of many reasons the perfect eye argument by creationists is utter bullshit.
themeatbridge@lemmy.world 5 weeks ago
Ugh that drives me crazy. The human eye is a perfect example of observable evolution. Organisms exist with every stage of eye development, from a photosensitive spot to a more advanced convergent evolution of our eye. And the human eye is poorly designed for it’s current use, resulting in a significant percentage of people requiring corrective lenses.
Quill7513@slrpnk.net 5 weeks ago
most of the dipshit “the eye is to perfect to have evolved” people also have cheap optics on their rifles. something to think about
floofloof@lemmy.ca 5 weeks ago
It’s a good example of evolving towards a local maximum then being unable to travel through a valley to a more optimal design. As such it confirms exactly what evolutionary theory would predict, and not what “intelligent design by an omniscient creator” would predict.
Catoblepas@piefed.blahaj.zone 5 weeks ago
Clearly this means God’s chosen are the cephalopods.
pennomi@lemmy.world 5 weeks ago
🧑🚀🔫🐙 Always have been.
deus@lemmy.world 5 weeks ago
In the lore of Lord of the Rings, it is said that the supreme being of that universe personally created both men and elves and since men were his favorite creations, he gave them the gift of… having pretty short lives (wow, thanks). Well, octopuses have a much shorter lifespan than us, so if our universe’s creator is anything like the Middle Earth’s then there’s a good chance they are his favorites.
TomArrr@lemmy.world 5 weeks ago
As someone with chronic back pain, eyes are the least of my issues with creationists theories
tetris11@lemmy.ml 5 weeks ago
exactly, bananas - amirite?
dave@feddit.uk 5 weeks ago
Yeah, my eyes are so perfect, I read that as ‘cartoonists’ and spent a good few minutes confused.
xx3rawr@sh.itjust.works 5 weeks ago
Bbb-but the bananas fit my hands!
Acklavidian@lemmy.world 5 weeks ago
Relevant video: youtu.be/2X1iwLqM2t0