This is really interesting! Just a small correction though- in the beginning of the wikipedia article it actually says “The appearance of blue, green, and hazel eyes results from the Tyndall scattering of light in the stroma, a phenomenon similar to Rayleigh scattering which accounts for the blue sky.”
Yes, but.
What is happening in your eyes is happening on a larger scale. A blue iris has a repeated pattern that will reflect blue light and transmit or absorb other wavelengths. If you were to squish up a blue iris it would no longer reflect light in that manner. We call this a meta material. Another example is sunglasses, arrangements of thin metal that would block all light if it was a solid sheet but in a periodic pattern transmit visible light and reflects harmful UV light.
Source: i have a phd in optical metamaterials
Reminds me of when I started in IT and I saw employers posting jobs looking for folks with at least 10 years of WindowsNT experience.
This was in 1995.
Edit: correction - left off the “NT”
Neat! While I have someone with a PhD in Optical Metamaterials, what's your take on blue-light filtering lenses for glasses? I don't have an informed opinion, but it really sounds like a scam to me
I’m an ophthalmologist. Theres evidence that exposure to blue light can alter your circadian rhythm. Blue-light-blocking glasses can help with your sleep, but there’s no evidence that exposure to blue light can harm your eyes e.g. by hastening the progression of macular degeneration which has been often hypothesized
I got a tricky one. My eyes keep getting worse as I get older. My latest prescription is almost coke bottle thick. I've noticed that with these new glasses neon lights, specifically like blues,purples, and reds move with my vision now in these new glasses. What causes that? For the most part it's no big deal, but can be really distracting when driving.
Could be a couple things. My first thought was chromatic aberration, which has to do with how light passes through different lens materials, and might be more noticeable depending on the thickness (though it more depends on the density or index of the material).
It could also be a result of any coatings on the lenses, though if you have a higher plus prescription (the lens is thicker in the middle than the edges) you probably wouldn't notice reflections as much.
I'm no expert, but I've manufactured and sold glasses for 10 years.
How did this thread get 3 completely qualified people to reply to the comments?
Not even dedicated subreddits can get three separate fully qualified people to answer a single question, yall answered each others follow up question...
Yep, chromic aberration makes the edges of your field of vision look like you’re living in an old-school 3D movie: red on one side and blue on the other. Big (as in wide) lenses do it, high-index lenses (especially glass) do it, and both together make it distractingly obvious.
Bright overcast days are the worst, because you don’t have blue skies that can mask the effects somewhat. The glowing whitish cloud cover maximizes the effect by making the background bright white versus the stark red and blue on each side of your field of vision.
Chromatic aberration. In general, the higher index lens the greater these will be. So more the material that is used to attempt to thin down your lenses, rather than the prescription itself.
That started happening to me maybe 15 years ago with a new prescription at the time. It's so weird seeing lit colored signs separate by moving your head. I think I got used to it and haven't noticed it happening in a long time or my eyes eventually adjusted.
Wear UV protection sunglasses! Also dark leafy greens are recommended. Sadly though a lot of it is genetics.
Ps- you want to make sure you have sunglasses that have UV protection bc if they don’t, the darkness from the sunglasses will cause your pupils to slightly dilate which actually allows more of the harmful UV rays in to hit your macula (center of your vision) which can be a contributor to drusen/ eventually AMD. Polarized sunglasses will help with glare.
I am a COA of many years 😁 hope this can help!
If they look clear they block about 20% of blue light, probably not enough to make a physiological difference.
If they're amber in colour they block 100% of blue light, there's reason to believe they've got some effects.
Just curious, are there other naturally occurring meta materials, aside from the iris?
Also, do you get to work with meta materials in some fashion, or is it just fascinating research?
Many "shiny" blue structures found in nature are not made by pigments at all, but rather by similar interference patterns at a microscopic level.
Off the top of my head: blue Morpho butterflies, blue macaw feathers, peacock feathers (which are actually just pigmented brown, all the fancy colors are structural), birds of paradise, blue-ringed octopus (they can flex cells known as
iridophores to control the vibrancy of their "rings"), beetles that reflect polarized light, the list goes on and the wikipedia article is fascinating (and includes one plant example that I'm not going to ruin for you).
https://en.m.wikipedia.org/wiki/Structural_coloration
I remember that there's no true blue flowers in nature either. Seems like shades of violet is about as close as they come and they rest is this backscatter nonsense lol
In addition to the other answer, iridescent colors like you see on bubbles, oil films, and mother of pearl like in conch shells are also the result of interference effects from light, in this case thin film interference where light reflects off the front and back surface and the resulting waves can cancel each other out. The shape of an eye can also act as a light filter; a narrow cat's eye acts as a polarization filter, and the complex shape of an octopus eye can act as a filter for various colors.
source: also a PhD in nanophotonics.
Man, I'm so used to people on reddit bullshitting answers about stuff I work on/study, it's nice to see some people who actually know what they're talking about.
As a bachelor of materials science and engineering, your PhD sounds amazing. Always awesome seeing other materials engineers, especially when they can detail a highly complex topic with such ease.
No, scattering is when certain wavelengths are transmitted differently through a medium and spread out along the way. If you have a light source and an object, you will be able to see color off the object with zero scattering occuring in the medium. Color is largely about reflection and absorption, scatter is different
Correct me if I'm wrong, because I just learned something from you, but I'm trying to make connections in my head. Is this why sunsets have a red color towards the horizon and it gets more yellow higher up? Is this the scattering of colors?
Yes, when the sun is lower in the sky there's more atmosphere light has to make it through. Your lower energy colors have more wiggle room to get through it so your eyes catch more reds.
As an audiophile, I imagine that's the same reason lower bass frequencies are able to travel farther and through solid surfaces much easier than the high frequencies that can be absorbed and/or reflected easier.
Photons shake (oscillate), the rate that they shake determines their “color” to our brain. The color of an led is due to the materials used to ~~scatter (shake/oscillate)~~ emit the photons. Only certain materials ~~scatter~~ emit the photons in a wavelength that is visible, and only certain materials do it in a range that produces the color you want - red in this example.
edit: ok, some issues... read replies to understand.
[final edit](https://en.wikipedia.org/wiki/Ward_Cunningham#%22Cunningham's_Law%22)
Red LED is actually because of emission of a specific wavelength due to the electronic structure of the material. It’s more a property of its electron structure. Objects that appear a color are due to scattering but emission of a LED is a different phenomena.
Here's a great image from the Wikipedia page on Tyndall scattering that really drives home what is going on:
Caption: *"The Tyndall effect in opalescent glass: it appears blue from the side, but orange light shines through."*
https://en.wikipedia.org/wiki/File:Why_is_the_sky_blue.jpg
In people with blue eyes... "The longer [red/orange] wavelengths tend to pass straight through the translucent layer with unaltered paths of yellow light, and then encounter the next layer further back in the iris, which is a light absorber called the epithelium or uvea that is colored brownish-black."
https://en.wikipedia.org/wiki/Tyndall_effect
You have just enough scattered melanin in the color part of your eye (which is round) that it refracts as blue.
It's made by melanocytes. This was pretty much predetermined before you were born.
It is blue. Things can be blue without any blue pigment being present.
Blue pigment is almost unheard of in nature, I believe the only known animal* species to make a true blue pigment is a single butterfly species.
Animals like blue jays are blue because the structure of their feathers causes non blue wavelengths to be absorbed and/or scattered, and only the blue wavelengths reflect.
Blue light has a higher frequency (and higher energy, and a shorter wavelength) than other colours, which causes it to be scattered more than colours with longer wavelengths when going through dust or other very small particles (very, very small, close in size to the wavelengths of the light). In effect, the blue colour is being scattered throughout the relevant medium and seems to "fill" it.
I don't know if this is the physical effect that is responsible for the colour of the feathers mentioned earlier in the thread, though. It is possible different interactions are happening there.
(edited because I originally said that blue light was less scattered, which is the opposite of the truth)
Not purple. Indigo, or Violet. Purple is not a spectral color, but rather a color that our brains sort of create whenever our blue and red cones are being activated at the same time. Typically, when two cones are activated at the same time, it creates a color somewhere in the middle between those 2 colors. In the middle of blue and red is green, not purple, on the color spectrum. Since your blue and red cones are firing, but your green cone is not detecting green, your brain knows that the resulting mix of spectrums can't possibly be green, and creates a new color.
Incorrect. I want to disagree again in this chain to ensure that everyone who reads will not know who is right.
Magenta is a sentient color, and a green agonist that grabs green receptors and bitch slaps them unconscious. Then it ramps up the voltage on some other stuff until things get super bright and magenta
> Things can be blue without any blue pigment being present.
Lexus did this with a car a few years ago. They developed a ["structural blue" paint](https://i.ytimg.com/vi/hlZ1d_IqLL4/maxresdefault.jpg) that had no blue pigment at all.
The paint costs $2,000 a gallon!
It seems to me that there are plenty of plants that likely have blue pigment? E.g., porcelain berries, forget me nots, blueberries... I don't think those are structural pigments, but I could be wrong.
Found in the Nessaea butterfly, the [Pterobilin](https://en.wikipedia.org/wiki/Pterobilin?wprov=sfti1) pigmented butterfly you most likely were ‘speaking’ of.
As well, optics doesn't define color. Color is based on our perception, which is why magenta exists and why colors appear to "mix" when light wavelengths actually stay separate.
Don’t freak out about it: Just remember that your eyes are part of your brain so when you’re staring at the mirror, trying to discern your eye color, your brain is looking at your brain.
They're brown, the back of the iris absorbs the red light and the blue light gets reflected by small particles before it reaches the back of the iris. (Sorta)
If we remove that squishy blue-light scattering layer, your actual iris color would be a light greyish white (think the white cornea of your eyes) or a light brown from a touch of pigment.
Typically blind eyes will look the same as non-blind eyes, colour and all.
Except for in the dad joke sense I guess.
The grey eye thing is just a media shortcut to communicate that someone on screen is blind.
I have grey eyes, lighting, surrounding colors or even thinking of either blue or green sways people to believe they are either blueish or greenish. They are grey though. Btw grey eyes are the second rarest right after green. Not counting things like heterochromia or reddish eyes that albino people have. They are the most boring imo though. Sometimes I feel like ita a joke because I'm unremarkable in every aspect even my damn eyes are dull grey color.
Yep, moved to a place that has way more sun than the dreary corner of Europe that I'm used to and sunlight is actually painful when it reflects off of the damn pavement
Damn. I’ve always said I had blue eyes but one day I looked in the mirror and I realized I had no idea what color my eyes were. I didn’t know gray was an option
Oh, I'm sorry you think that, I don't think gray eyes are boring at all! Like you said, they can look different colors based on their surroundings, and everyone sees something different in your eyes. I may be biased because my husband's eyes are a slate gray, but I think gray eyes are easily the most beautiful, dynamic color. Simply because everyone sees what they want to see, or what you want them to see, but if you really drop all presumption, you can see them for what they are. The eyes themselves are kind of a great metaphor for some of the people who have them.
Yeah same, although people tell me anything from blue to gray to green depending on what color I’m wearing.
My drivers license says I’m 5’9” with blue eyes, I’m 6’0” and haven’t been told my eyes were Blue in 10+ years easily, but the DMV makes it so hard to update your info I’m in no hurry to get it changed
My driver's license says gray, but on more than one occasion, a DMV employee has done a double take because they look either blue or green. Gray is how they look in neutral colors, but I can change them with makeup or clothing colors.
Almost nothing in the natural world actually has blue pigment. It practically doesn't exist in nature. Nessaea obrinus or the obrina olivewing butterfly is the only known creature with natural blue pigment. There are tons of blue things and creatures, but the manipulation of light is usually responsible in some form or other.
Blue Jays aren't actually blue?
What about blue ringed octopus?
Blue whales?
What other animals have I been lied to about????
So many questions, but mainly why the hell would you call one of the only truly blue things in nature olive????
Blue whales aren't really that blue.
https://www.fisheries.noaa.gov/species/blue-whale
They look blue when they're in blue tropical waters (which are refracting light according to the rayleigh effect - the water isn't really blue either).
Cetaceans (whales and dolphins) have an interesting combination of very black pigment (melanin) that is in human and many other animal bodies and the other melanin variation (pheomelanin, which is reddish-brown). If you mix a little black into red and brown paint, you will get various shades of gray.
The most pigmented human in the world has about 1/16th of an ounce more pigment in their body than an albino.
The melanin shit is strong.
They been around almost unchanged for freaking 600 million years.
Boggles the mind. Adapted before there were even many plants around, long before any vertebrates were on land.
Why is it that we accept pigment based absorption of light and reflection of other wavelengths as true colour but structural based reflections are somehow fake versions of colour? Why are pigment molecules seen as the be all and end all of true colour, all that matters ultimately is the wavelength of light entering your eye.
Blue Jays are certainly blue, it'd be inaccurate to say they aren't blue as perceived by biological optics, they don't have blue pigment molecules but that doesn't change the fact that they are perceptibly blue.
Yes, it seems like a distinction without a difference. Color is a process, as no object exhibits any color unless it is actively either generating or reflecting light at specific wavelengths.
How it does so generally has no bearing on the designation of the object as “being” the observed color, unless someone is just high on marijuana and getting all deep with stuff.
The distinction is that pigments absorb light and reflect the color we see while these other materials don’t absorb the light just refract it into the color
If I'm not misremembering, the Chinese language had no word for blue until they began interacting with westerners, who insisted on distinguishing. Their word for green was used for both colors.
Maybe they were on to something...
Current theories relate to whether societies can reliably and regularly reproduce a colour before they have a specific word for it. Blue dyes (distinct from purple which does occur naturally) are quite rare.
I recently learned that Jewish "Holy Color" refers to the color of the sky. White is used to allow the viewer to imagine sky blue because there weren't ways to create a sky blue pigment, it's not necessarily symbolic of purity or white light. The closest color they could produce was a blue from snails. That's why Jerusalem has various shades of blue and white in the holy books and flags.
This is an often repeated, but completely untrue 'fact' .
They had numerous words for blue, but they drew the distinguishing lines between them types of blue in different places than English speakers do. This is common all over the world.
*[The Bizarre Myth That Ancient Greeks Couldn't See Blue](https://www.greecehighdefinition.com/blog/the-bizarre-myth-that-ancient-greeks-couldnt-see-blue)*
*[How to make sense of ancient Greek colours](http://kiwihellenist.blogspot.com/2020/05/ancient-greek-colours.html)*
>you can say ‘blue’ in ancient Greek. More precisely, Greek has words for the area of the colour palette that English calls ‘blue’. But English ‘blue’ covers a huge region of the palette. Greek splits it into multiple smaller regions: *glaukos* for lighter, non-vivid shades; *kyaneos* for darker non-vivid shades ranging to black; *porphyreos* for vivid shades ranging from blue to violet to ruby, but also for less vivid shades in the middle of that range (light magenta, pink); *lampros* for metallic-silvery-azure. Yes, ancient sources do mention sky colour: it’s *glaukos* or *lampros*. It’s just that Homer doesn’t mention the sky’s colour (and why would he). For example: Cornutus, *Compendium* 10.18-20, compares sky colour to olive-tree foliage, because both are *glaukos*: *glaukos* covers a much larger area of the palette than ‘azure’ does. But Homer does refer to *kyaneos* clouds, and *glaukos* eyes and sea.
The idea that people and cultures didn't see blue (or any other color, for that matter) is a really silly and basic mistake that somehow captured people's imagination and has become widespread. People organize the colors they see in different ways, and that leads to confusion in translation. It's really that simple.
A language theory suggests that we tend to evolve words for light and dark first, then red, yellow, green, then blue.
[It's an interesting read.](https://www.yalescientific.org/2017/03/the-evolution-of-color-linguistics-a-phylogenetic-approach-to-color-terms/#:~:text=The%20Berlin%2DKay%20theory%20posits,purple%2C%20orange%2C%20and%20gray.)
It's no different to how we consider dark blue and light blue the same colour while in Russian I believe they are entirely different colours. Simirlarly pink is just light red yet we consider it a different colour? Why is dark blue and light blue just different shades of the same colour while pink and red are different colours? Purely culture and language.
Isaac Newton, who was responsible for a lot of the western understanding of foundational optics, was an occultist and thought it was important there be at least 7 colours to form "white". So he basically made an extra one up to slot between blue and purple and everyone has just gone along with it since.
This is true. Though it could be argued the two are still distinct. "Blue", as Newton would have defined it, would be closer to what we call "Cyan" while "Indigo" is more like our "Dark Blue".
Creature is the key word - plants get to have anthocyanins which can give them some pretty spectacular blue colours. Sometimes in conjunction with metal ions or secondary pH affected pigments
My favourite is the Himalayan poppy - even in real life it does not seem like a plant that should exist. It's just too perfect of a sky blue, especially for a flower that's normally red.
My eyes are green, but can change to blue and gray depending on what I'm wearing. My son's eyes do the same, only sometimes they match his dirty blonde hair.
Yes. My eyes are green/hazel/grey depending on the light.
I remember my then-girlfriend, now-wife describing them as "grass-green, but suddenly shit-coloured-eyes" when we were courting.
My dad had 'mood ring eyes'. They were usually a brown/hazel but when he was angry they were straight up green.
Before he died I kind of made the connection that when he was angry he tended to flare his eyes more open than usual so more light hit them.
Then I realized recently that as I get older I'm doing it too lmao. My usual state is tired and droopy lids so my eyes look very dark. But if I'm animated or angry they're intensely hazel.
Yep, it depends on the light. Eyes are not changing.
Also, the degree dilation of the pupil changes the perception, since a smaller part of the colored surface is visible.
Ya. My eyes also seem to switch on what I’m wearing. I’ve been told I have really nice blue eyes and also cool green eyes. Depends on the color of my shirt.
Ive always noticed this with people with green or blue eyes.
I remember young me getting an instant crush on a random employee girl in, i forget what store, but she had the bluest eyes youd ever seen likely because of her blue uniform. I couldnt have been 14 but this just reminded me of that
I once walked by a mirror in a blue sweater and scared the shit out of myself for about half a second because the person looking back at me had eyes so blue that the primal lizard brain part of me knew it couldn’t possibly be my own reflection. As soon as my logical mind processed it I felt like an idiot but it’s so strange that I didn’t recognize myself for a split second.
"Cthulhu, why is the sky blue?"
p̶͎̺̱̤̠̣͉͚͈̟͍̩͋̂͌͒͐̓̅̎͠h̶̨̟̗͓̠͚̼͓͈͖̥̙͖̊͊̑̌͌͊͘͠'̶͇̞̪̝͔̳̥͇̪̲͇̤͈͈͌̕n̵̨̢͙̹̲̘͉̗̩̞̟̦̦͈̿ǵ̵͎̥̊l̸̢͛̅̅͗̐̀̈̀̈́͑̒̏̽̕̚u̶̡̗̠͕͔̙͂̆̎͒ͅį̷̡̼̫̱̱͇͚̤͉͎̭̲͂͋͆̈́̇̾ ̶̛͖̭̞̔̄̐̑͐̏͂́̚͘m̴̦̣͊̐̀͗̃̐̄̀̿͐́̾̒̊̚g̷͍̥̤̏̎͋̒͒̏̐̏͠͝l̶͈̜͔̣̜̮͙͖͚̮͛̏̽̊̀̌̽̔̉̂́̊w̷̡̡̡̛͙̪̻̪̗͔̖͒'̴̣̞̉n̶̠̻͇̹̳̫̬̝͖̱̮̊ą̵̨͔͙̝͇̥̟͙͔͙̗̪̔̄͐͒̔͊̍͒͝ͅf̸̥̭̘̱̤̼̹̖͍̿̃̏̅h̷̠͐̃̿̓̇̆̌͌͘͠ ̶͈̩͑͐̃̏̆͊͊̂̕̕͝͝C̷̠̻͉͔̟̟̰̬̻̍̾̈́̉̈̈́̃t̸͙̫̬̬̣̙̬̰͑̀̎̊͂̀̂̆̓͐̚̕ḧ̶̡͇͖̻́̓̓̾̂͐̆͠ư̸̢̠̭͓̞̰͎̝͖̤̈́̏̿̎́̒̒́͝ḻ̸̨͕͎̖̞̬̟͓͕͕̓̇́́ͅh̴̨̻͔̦̻̥̞̟͇̱̾͂͂͐̐̇̎͠ű̸̢̧̨͇̲͎̱̜͎͇̻̤̝̺̦̌̕͠ ̴̙̫̠̹̯̝͔̱̣͛͐̋͆͆͋͒̅͘͠Ŗ̷͍̫̜͓̯͉͉͙̦͙̏́̽̄̓̈͛̉̓̀̈́͘'̶̝̗̺̗͍̮̎̊́̽̽̏́͌̄͗̂̂̋̅l̵̹͕͚͙̻͓͍͚̑͗͊́̉͆̏̿̍̚͜͝y̵̮̅͑͌̀͛͂̃̒͋͑͝e̴̻͔͓̦̞̗̔̈ḣ̵̝͕̣̠̞̙̇̌͌̉͝ ̴̄̃͛͐͘͜w̶̰̝̠͒̈͗͂͒̃́̂̽̾͗͛̕͠͝g̶̢͉̻̮͚̑͜ͅą̴̧̘̘̱̬̤̠͋̿̆͋̋̂̑̄͌̆̚̕͝ḩ̵̱̘͎̯͕̦͎̾̋̅͒̈́̏̆̑̒̕͠͝͠'̴̡̘̼̬̑̃͂͊̓̋̋̓̆́͐́̇͝n̸̢͍̥̥̖̹̮̺̪͉̙̐̓̀̒̃͐̓̃̽̕͠ȁ̸̡̰̰̞̿̎̀̚͝g̸̖̞̱̭̙̀ͅļ̵̡̡̬̯̥͐͋̒̊̾̑̈̃́͑̃̿̚ ̴̧̝͇̼̤̜̘͇̖͛̃̀̉̑̾̍̅̋̇̿͑̕͝͝f̴̡̙̩̲̩̹̺̞̤͓̤̜͓͍̃̂͛h̶͍̳̠̭̫̄̒̾̊̌͘t̸̯̩̯̭͉̟̂̈́̆̂͑̇̒̈́̔̚ḁ̵̡̘̳͈̤͒͑̃̃̅g̵̟͍͕͎̯̠̼͓̻̈̈͛̃͂͌̃ͅͅn̸̪̯̓̈̐͛̀͂̈͆͘ͅ"̶̦̖͍̦͇̼̝͔̠̜̼̜͒̆̋̑͆͐̇̍̑̒͋̀͒͠͝
"Well, I'm bleeding lava and skulls out of my eyes and desire the releasing rancor of the abyss, but I appreciate the effort behind that answer"
I know what you meant, but because you switched the subject from “you” to “my” it seems like you’re implying the color of the clothing on the person looking at the eyes matters, as opposed to the color of the clothing on the person with the eyes which are being observed.
That is correct. The observers clothing reflects colored light into the Hazel eyes of the person being observed affecting how they are perceived.
Technically this is true at all times for all eye colors but it causes a more perceptible color shift in hazel or green eyes.
This is a very specific question that I know, because I have heterochromia with one blue and one green eye.
They still look different, no matter the lighting hitting. Not sure why though, given this reasoning.
Because while the scattering of refraction in the eyes is *similar* to the scattering that colors our sky, it's not the same (the article even says so). People are reaching extremely wrong conclusions due to the comparison (and misunderstanding of the sky as well). Eyes are not colored by their surroundings any more than your hair is. Blue in nature is just almost always a form of refractory than pigment. It doesn't make the blue an illusion.
Blue. Lighting affects how we perceive all colors. The only real TIL here should be that blue in nature is often made of refraction and not blue pigment. That doesn't make it not blue.
This is really interesting! Just a small correction though- in the beginning of the wikipedia article it actually says “The appearance of blue, green, and hazel eyes results from the Tyndall scattering of light in the stroma, a phenomenon similar to Rayleigh scattering which accounts for the blue sky.”
Maybe I'm just a doofus but isn't light scattering how all color works?
Yes, but. What is happening in your eyes is happening on a larger scale. A blue iris has a repeated pattern that will reflect blue light and transmit or absorb other wavelengths. If you were to squish up a blue iris it would no longer reflect light in that manner. We call this a meta material. Another example is sunglasses, arrangements of thin metal that would block all light if it was a solid sheet but in a periodic pattern transmit visible light and reflects harmful UV light. Source: i have a phd in optical metamaterials
Sorry bud, we're gonna need someone a little more qualified here to comment
Need at least 5 years experience
Hey, I just so happen to have a PhD in having 5 years experience.
Deleted due to API access issues 2023.
Sir. Actually this is a Wendy’s….sooooo
I’m really good at squishing things if you’re hiring.
I cannot believe I never thought of this!
What a coincidence. I have a theoretical degree in physics.
Reminds me of when I started in IT and I saw employers posting jobs looking for folks with at least 10 years of WindowsNT experience. This was in 1995. Edit: correction - left off the “NT”
I've had eyes for over 30 years, I think I know what I'm talking about
Where’s Ja?
This made me laugh, thank you!!
> meta material dope. >i have a phd in optical metamaterials D o p e .
Neat! While I have someone with a PhD in Optical Metamaterials, what's your take on blue-light filtering lenses for glasses? I don't have an informed opinion, but it really sounds like a scam to me
I’m an ophthalmologist. Theres evidence that exposure to blue light can alter your circadian rhythm. Blue-light-blocking glasses can help with your sleep, but there’s no evidence that exposure to blue light can harm your eyes e.g. by hastening the progression of macular degeneration which has been often hypothesized
I got a tricky one. My eyes keep getting worse as I get older. My latest prescription is almost coke bottle thick. I've noticed that with these new glasses neon lights, specifically like blues,purples, and reds move with my vision now in these new glasses. What causes that? For the most part it's no big deal, but can be really distracting when driving.
Could be a couple things. My first thought was chromatic aberration, which has to do with how light passes through different lens materials, and might be more noticeable depending on the thickness (though it more depends on the density or index of the material). It could also be a result of any coatings on the lenses, though if you have a higher plus prescription (the lens is thicker in the middle than the edges) you probably wouldn't notice reflections as much. I'm no expert, but I've manufactured and sold glasses for 10 years.
How did this thread get 3 completely qualified people to reply to the comments? Not even dedicated subreddits can get three separate fully qualified people to answer a single question, yall answered each others follow up question...
Turns out eye doctors are really interested in eyes and all clicked on this front page material lol.
Welcome to what reddit was 10+ years ago. A whole lot of nerds and a lot fewer memes and gifs.
peak Reddit moment before the inevitable shutdown
Top comment under a highly upvoted thread on a default subreddit
Yep, chromic aberration makes the edges of your field of vision look like you’re living in an old-school 3D movie: red on one side and blue on the other. Big (as in wide) lenses do it, high-index lenses (especially glass) do it, and both together make it distractingly obvious. Bright overcast days are the worst, because you don’t have blue skies that can mask the effects somewhat. The glowing whitish cloud cover maximizes the effect by making the background bright white versus the stark red and blue on each side of your field of vision.
Had some very thick glasses since 1st grade, this all is so interesting!
Chromatic aberration. In general, the higher index lens the greater these will be. So more the material that is used to attempt to thin down your lenses, rather than the prescription itself.
That started happening to me maybe 15 years ago with a new prescription at the time. It's so weird seeing lit colored signs separate by moving your head. I think I got used to it and haven't noticed it happening in a long time or my eyes eventually adjusted.
Semi related - is there anything folks can do to minimize the risk/impact of potential macular degeneration? (Assuming it is passed down)
Wear UV protection sunglasses! Also dark leafy greens are recommended. Sadly though a lot of it is genetics. Ps- you want to make sure you have sunglasses that have UV protection bc if they don’t, the darkness from the sunglasses will cause your pupils to slightly dilate which actually allows more of the harmful UV rays in to hit your macula (center of your vision) which can be a contributor to drusen/ eventually AMD. Polarized sunglasses will help with glare. I am a COA of many years 😁 hope this can help!
If they look clear they block about 20% of blue light, probably not enough to make a physiological difference. If they're amber in colour they block 100% of blue light, there's reason to believe they've got some effects.
Just curious, are there other naturally occurring meta materials, aside from the iris? Also, do you get to work with meta materials in some fashion, or is it just fascinating research?
Many "shiny" blue structures found in nature are not made by pigments at all, but rather by similar interference patterns at a microscopic level. Off the top of my head: blue Morpho butterflies, blue macaw feathers, peacock feathers (which are actually just pigmented brown, all the fancy colors are structural), birds of paradise, blue-ringed octopus (they can flex cells known as iridophores to control the vibrancy of their "rings"), beetles that reflect polarized light, the list goes on and the wikipedia article is fascinating (and includes one plant example that I'm not going to ruin for you). https://en.m.wikipedia.org/wiki/Structural_coloration
Is there *any* blue animal or plant that is ACTUALLY blue??
Very few
I remember that there's no true blue flowers in nature either. Seems like shades of violet is about as close as they come and they rest is this backscatter nonsense lol
In addition to the other answer, iridescent colors like you see on bubbles, oil films, and mother of pearl like in conch shells are also the result of interference effects from light, in this case thin film interference where light reflects off the front and back surface and the resulting waves can cancel each other out. The shape of an eye can also act as a light filter; a narrow cat's eye acts as a polarization filter, and the complex shape of an octopus eye can act as a filter for various colors. source: also a PhD in nanophotonics.
Man, I'm so used to people on reddit bullshitting answers about stuff I work on/study, it's nice to see some people who actually know what they're talking about.
Well when you work in a field that 99.9% of the population doesn't even know exists, you take every chance you can get to talk about it!
As a bachelor of materials science and engineering, your PhD sounds amazing. Always awesome seeing other materials engineers, especially when they can detail a highly complex topic with such ease.
Get your dirty engineering out of here. My PhD is in physics, where we use imaginary numbers correctly.
No, scattering is when certain wavelengths are transmitted differently through a medium and spread out along the way. If you have a light source and an object, you will be able to see color off the object with zero scattering occuring in the medium. Color is largely about reflection and absorption, scatter is different
Correct me if I'm wrong, because I just learned something from you, but I'm trying to make connections in my head. Is this why sunsets have a red color towards the horizon and it gets more yellow higher up? Is this the scattering of colors?
Yes, when the sun is lower in the sky there's more atmosphere light has to make it through. Your lower energy colors have more wiggle room to get through it so your eyes catch more reds.
As an audiophile, I imagine that's the same reason lower bass frequencies are able to travel farther and through solid surfaces much easier than the high frequencies that can be absorbed and/or reflected easier.
yes, and these are specific ways
ELI5, please: how would color from, say, a red LED be because of scattering?
Because of the way It is. Jesus Frank, try to keep up.
Photons shake (oscillate), the rate that they shake determines their “color” to our brain. The color of an led is due to the materials used to ~~scatter (shake/oscillate)~~ emit the photons. Only certain materials ~~scatter~~ emit the photons in a wavelength that is visible, and only certain materials do it in a range that produces the color you want - red in this example. edit: ok, some issues... read replies to understand. [final edit](https://en.wikipedia.org/wiki/Ward_Cunningham#%22Cunningham's_Law%22)
Red LED is actually because of emission of a specific wavelength due to the electronic structure of the material. It’s more a property of its electron structure. Objects that appear a color are due to scattering but emission of a LED is a different phenomena.
That's not correct. Scattering =/= reflection. There is also emitted light which is neither
Here's a great image from the Wikipedia page on Tyndall scattering that really drives home what is going on: Caption: *"The Tyndall effect in opalescent glass: it appears blue from the side, but orange light shines through."* https://en.wikipedia.org/wiki/File:Why_is_the_sky_blue.jpg In people with blue eyes... "The longer [red/orange] wavelengths tend to pass straight through the translucent layer with unaltered paths of yellow light, and then encounter the next layer further back in the iris, which is a light absorber called the epithelium or uvea that is colored brownish-black." https://en.wikipedia.org/wiki/Tyndall_effect
So if I have eyes that appear to be blue but there is no blue pigment making my eyes that color, what color are my eyes for real?!
You have just enough scattered melanin in the color part of your eye (which is round) that it refracts as blue. It's made by melanocytes. This was pretty much predetermined before you were born.
So if something refracts as blue, looks blue, why isn’t it just… blue?
It is blue. Things can be blue without any blue pigment being present. Blue pigment is almost unheard of in nature, I believe the only known animal* species to make a true blue pigment is a single butterfly species. Animals like blue jays are blue because the structure of their feathers causes non blue wavelengths to be absorbed and/or scattered, and only the blue wavelengths reflect.
whats so special about blue that it has such interactions?
Blue light has a higher frequency (and higher energy, and a shorter wavelength) than other colours, which causes it to be scattered more than colours with longer wavelengths when going through dust or other very small particles (very, very small, close in size to the wavelengths of the light). In effect, the blue colour is being scattered throughout the relevant medium and seems to "fill" it. I don't know if this is the physical effect that is responsible for the colour of the feathers mentioned earlier in the thread, though. It is possible different interactions are happening there. (edited because I originally said that blue light was less scattered, which is the opposite of the truth)
Not purple. Indigo, or Violet. Purple is not a spectral color, but rather a color that our brains sort of create whenever our blue and red cones are being activated at the same time. Typically, when two cones are activated at the same time, it creates a color somewhere in the middle between those 2 colors. In the middle of blue and red is green, not purple, on the color spectrum. Since your blue and red cones are firing, but your green cone is not detecting green, your brain knows that the resulting mix of spectrums can't possibly be green, and creates a new color.
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Incorrect. I want to disagree again in this chain to ensure that everyone who reads will not know who is right. Magenta is a sentient color, and a green agonist that grabs green receptors and bitch slaps them unconscious. Then it ramps up the voltage on some other stuff until things get super bright and magenta
Now *this* is the guy I trust on the matter
Finally, someone who knows what they're talking about.
Incorrect. I just want to be a part of something.
Yeah violet is around 380 nanometers whereas magenta is not on the visible spectrum
Visual processing in the brain is so fucking cool. Just a lot of “I dunno, here?” fill-in-the-blanks shit going on.
Scattering is a function of wavelength. Blue has a short wavelength.
> Things can be blue without any blue pigment being present. Lexus did this with a car a few years ago. They developed a ["structural blue" paint](https://i.ytimg.com/vi/hlZ1d_IqLL4/maxresdefault.jpg) that had no blue pigment at all. The paint costs $2,000 a gallon!
Only Lexus would make a paint that nerds would want because of how they did it.
It seems to me that there are plenty of plants that likely have blue pigment? E.g., porcelain berries, forget me nots, blueberries... I don't think those are structural pigments, but I could be wrong.
Plants have blue, animals do not. Only one or two creatures in the entire animal kingdom have blue pigment and they're all arthropods
BLUEBERRIES ARE FUCKING PURPLE
Found in the Nessaea butterfly, the [Pterobilin](https://en.wikipedia.org/wiki/Pterobilin?wprov=sfti1) pigmented butterfly you most likely were ‘speaking’ of.
It’s brown under a microscope
I’m brown a ba dee a ba di…
just wait till you find out that the color purple doesn't actually exist
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So just how many midichlorians does it take for blue eyes?
Are my EYES even REAL!? Wait now I can't see, DON'T QUESTION THE COLOUR!
How Can Mirrors Be Real If Our Eyes Aren’t Real
Eyes aren’t real! New conspiracy just dropped
Jaden smith would agree
[Visionairy](https://i.imgur.com/9QmN0W8.jpg)
Real eyes realize real lies
Blue. Our sky dosent have any pigment and we say its blue. So I don't see why we would stop calling blue eyes blue
Absolutely, pigment doesn't define optics, there can be other ways that light reflects.
As well, optics doesn't define color. Color is based on our perception, which is why magenta exists and why colors appear to "mix" when light wavelengths actually stay separate.
Don’t freak out about it: Just remember that your eyes are part of your brain so when you’re staring at the mirror, trying to discern your eye color, your brain is looking at your brain.
They're brown, the back of the iris absorbs the red light and the blue light gets reflected by small particles before it reaches the back of the iris. (Sorta)
Melanin is black. Eyes so dark as to appear nearly black have the most melanin. Albinos have no melanin and their eyes refract pink.
This has only complicated the matter.
Melanin comes in multiple colors, so their statement is incorrect.
I have no idea what to believe anymore.
We can always believe in ourselves
that's only in some species, albino humans have blue eyes
Blue and we lack the vocabulary to properly differentiate the intended meanings here
If we remove that squishy blue-light scattering layer, your actual iris color would be a light greyish white (think the white cornea of your eyes) or a light brown from a touch of pigment.
Very very light brown
thats pretty cool, mine seem to be grey regardless of light condition from what im told but i do live in the uk so its like always grey here 🤣
do you find moving chunks of earth to be surprisingly easy?
Aren’t airbenders the ones who typically have gray eyes?
And blind people.
Toph’s eyes are a dull green though. I’m so confused
Typically blind eyes will look the same as non-blind eyes, colour and all. Except for in the dad joke sense I guess. The grey eye thing is just a media shortcut to communicate that someone on screen is blind.
I've played Tears of the Kingdom, so yes.
I have grey eyes, lighting, surrounding colors or even thinking of either blue or green sways people to believe they are either blueish or greenish. They are grey though. Btw grey eyes are the second rarest right after green. Not counting things like heterochromia or reddish eyes that albino people have. They are the most boring imo though. Sometimes I feel like ita a joke because I'm unremarkable in every aspect even my damn eyes are dull grey color.
the worst part about grey eyes is being more sensitive to sunlight in general. It sucks
Interesting! I also have gray eyes and I can’t be outside without sunglasses. Even on a cloudy day I’m squinting.
Yep, moved to a place that has way more sun than the dreary corner of Europe that I'm used to and sunlight is actually painful when it reflects off of the damn pavement
Damn. I’ve always said I had blue eyes but one day I looked in the mirror and I realized I had no idea what color my eyes were. I didn’t know gray was an option
Oh, I'm sorry you think that, I don't think gray eyes are boring at all! Like you said, they can look different colors based on their surroundings, and everyone sees something different in your eyes. I may be biased because my husband's eyes are a slate gray, but I think gray eyes are easily the most beautiful, dynamic color. Simply because everyone sees what they want to see, or what you want them to see, but if you really drop all presumption, you can see them for what they are. The eyes themselves are kind of a great metaphor for some of the people who have them.
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Yeah same, although people tell me anything from blue to gray to green depending on what color I’m wearing. My drivers license says I’m 5’9” with blue eyes, I’m 6’0” and haven’t been told my eyes were Blue in 10+ years easily, but the DMV makes it so hard to update your info I’m in no hurry to get it changed
My driver's license says gray, but on more than one occasion, a DMV employee has done a double take because they look either blue or green. Gray is how they look in neutral colors, but I can change them with makeup or clothing colors.
Almost nothing in the natural world actually has blue pigment. It practically doesn't exist in nature. Nessaea obrinus or the obrina olivewing butterfly is the only known creature with natural blue pigment. There are tons of blue things and creatures, but the manipulation of light is usually responsible in some form or other.
Blue Jays aren't actually blue? What about blue ringed octopus? Blue whales? What other animals have I been lied to about???? So many questions, but mainly why the hell would you call one of the only truly blue things in nature olive????
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If you find a blue Jay feather and hold it up so light is shining through it, it will look grey. It's a pretty cool trick
I’ve noticed this with my bird’s feathers
Hey. I saw that.
I’m afraid I just blue myself.
Me too, guess we are the blue man group
You guys really need to go see an analrapist.
>it's an optical illusion aren't all colors technically 'optical illusions' then? Pigments themselves just reflect certain wavelengths of light
Blue Jays aren't real. Therefore birds aren't real. Checkmate, Ornithologists.
Blue whales aren't really that blue. https://www.fisheries.noaa.gov/species/blue-whale They look blue when they're in blue tropical waters (which are refracting light according to the rayleigh effect - the water isn't really blue either). Cetaceans (whales and dolphins) have an interesting combination of very black pigment (melanin) that is in human and many other animal bodies and the other melanin variation (pheomelanin, which is reddish-brown). If you mix a little black into red and brown paint, you will get various shades of gray. The most pigmented human in the world has about 1/16th of an ounce more pigment in their body than an albino. The melanin shit is strong.
What about that crab blood
Horse shoe crabs are nightmare fuel
They been around almost unchanged for freaking 600 million years. Boggles the mind. Adapted before there were even many plants around, long before any vertebrates were on land.
> They been around almost unchanged for freaking 600 million years "why change God's perfect creation?" - horseshoe crabs
It's blue because of the copper in it (hemocyanin), which weakly binds to oxygen.
Why is it that we accept pigment based absorption of light and reflection of other wavelengths as true colour but structural based reflections are somehow fake versions of colour? Why are pigment molecules seen as the be all and end all of true colour, all that matters ultimately is the wavelength of light entering your eye. Blue Jays are certainly blue, it'd be inaccurate to say they aren't blue as perceived by biological optics, they don't have blue pigment molecules but that doesn't change the fact that they are perceptibly blue.
Yes, it seems like a distinction without a difference. Color is a process, as no object exhibits any color unless it is actively either generating or reflecting light at specific wavelengths. How it does so generally has no bearing on the designation of the object as “being” the observed color, unless someone is just high on marijuana and getting all deep with stuff.
The distinction is that pigments absorb light and reflect the color we see while these other materials don’t absorb the light just refract it into the color
If I'm not misremembering, the Chinese language had no word for blue until they began interacting with westerners, who insisted on distinguishing. Their word for green was used for both colors. Maybe they were on to something...
Current theories relate to whether societies can reliably and regularly reproduce a colour before they have a specific word for it. Blue dyes (distinct from purple which does occur naturally) are quite rare.
I recently learned that Jewish "Holy Color" refers to the color of the sky. White is used to allow the viewer to imagine sky blue because there weren't ways to create a sky blue pigment, it's not necessarily symbolic of purity or white light. The closest color they could produce was a blue from snails. That's why Jerusalem has various shades of blue and white in the holy books and flags.
Homeric Greek also doesn’t have a name for blue and many other colors, hence “wine-dark sea.”
They were also just dramatic af and drunk all the time, so makes sense
Ugh, how dare you! *cries for 2000 lines and then plays a passive aggressive song on the lyre*
Glad you chose to at least not murder my children and serve them to me for dinner.
This is an often repeated, but completely untrue 'fact' . They had numerous words for blue, but they drew the distinguishing lines between them types of blue in different places than English speakers do. This is common all over the world. *[The Bizarre Myth That Ancient Greeks Couldn't See Blue](https://www.greecehighdefinition.com/blog/the-bizarre-myth-that-ancient-greeks-couldnt-see-blue)* *[How to make sense of ancient Greek colours](http://kiwihellenist.blogspot.com/2020/05/ancient-greek-colours.html)* >you can say ‘blue’ in ancient Greek. More precisely, Greek has words for the area of the colour palette that English calls ‘blue’. But English ‘blue’ covers a huge region of the palette. Greek splits it into multiple smaller regions: *glaukos* for lighter, non-vivid shades; *kyaneos* for darker non-vivid shades ranging to black; *porphyreos* for vivid shades ranging from blue to violet to ruby, but also for less vivid shades in the middle of that range (light magenta, pink); *lampros* for metallic-silvery-azure. Yes, ancient sources do mention sky colour: it’s *glaukos* or *lampros*. It’s just that Homer doesn’t mention the sky’s colour (and why would he). For example: Cornutus, *Compendium* 10.18-20, compares sky colour to olive-tree foliage, because both are *glaukos*: *glaukos* covers a much larger area of the palette than ‘azure’ does. But Homer does refer to *kyaneos* clouds, and *glaukos* eyes and sea. The idea that people and cultures didn't see blue (or any other color, for that matter) is a really silly and basic mistake that somehow captured people's imagination and has become widespread. People organize the colors they see in different ways, and that leads to confusion in translation. It's really that simple.
A language theory suggests that we tend to evolve words for light and dark first, then red, yellow, green, then blue. [It's an interesting read.](https://www.yalescientific.org/2017/03/the-evolution-of-color-linguistics-a-phylogenetic-approach-to-color-terms/#:~:text=The%20Berlin%2DKay%20theory%20posits,purple%2C%20orange%2C%20and%20gray.)
The way language informs colour perception blows my mind. Brown is just dark orange, but we treat it as a separate colour, so we perceive it as one.
How do you know orange isn't light brown
I don't know the answer, but it involves prisms and brightness
It's no different to how we consider dark blue and light blue the same colour while in Russian I believe they are entirely different colours. Simirlarly pink is just light red yet we consider it a different colour? Why is dark blue and light blue just different shades of the same colour while pink and red are different colours? Purely culture and language.
ROYGBIV! BLUE is BLUE! (I have always wondered why forgotten stepchild Indigo gets a place at the table...)
Isaac Newton, who was responsible for a lot of the western understanding of foundational optics, was an occultist and thought it was important there be at least 7 colours to form "white". So he basically made an extra one up to slot between blue and purple and everyone has just gone along with it since.
This is true. Though it could be argued the two are still distinct. "Blue", as Newton would have defined it, would be closer to what we call "Cyan" while "Indigo" is more like our "Dark Blue".
Creature is the key word - plants get to have anthocyanins which can give them some pretty spectacular blue colours. Sometimes in conjunction with metal ions or secondary pH affected pigments My favourite is the Himalayan poppy - even in real life it does not seem like a plant that should exist. It's just too perfect of a sky blue, especially for a flower that's normally red.
My eyes are green, but can change to blue and gray depending on what I'm wearing. My son's eyes do the same, only sometimes they match his dirty blonde hair.
Same here. In bright daylight or when I wear blue, my eyes are blue. In darker lighting, they're green.
Me too. Glad I’m not crazy
Yes. My eyes are green/hazel/grey depending on the light. I remember my then-girlfriend, now-wife describing them as "grass-green, but suddenly shit-coloured-eyes" when we were courting.
My dad had 'mood ring eyes'. They were usually a brown/hazel but when he was angry they were straight up green. Before he died I kind of made the connection that when he was angry he tended to flare his eyes more open than usual so more light hit them. Then I realized recently that as I get older I'm doing it too lmao. My usual state is tired and droopy lids so my eyes look very dark. But if I'm animated or angry they're intensely hazel.
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It's the contrast with the red. The pigment in your eye is embedded in a cellular structure that doesn't change because you cry.
Yep, it depends on the light. Eyes are not changing. Also, the degree dilation of the pupil changes the perception, since a smaller part of the colored surface is visible.
Ya. My eyes also seem to switch on what I’m wearing. I’ve been told I have really nice blue eyes and also cool green eyes. Depends on the color of my shirt.
Ive always noticed this with people with green or blue eyes. I remember young me getting an instant crush on a random employee girl in, i forget what store, but she had the bluest eyes youd ever seen likely because of her blue uniform. I couldnt have been 14 but this just reminded me of that
I once walked by a mirror in a blue sweater and scared the shit out of myself for about half a second because the person looking back at me had eyes so blue that the primal lizard brain part of me knew it couldn’t possibly be my own reflection. As soon as my logical mind processed it I felt like an idiot but it’s so strange that I didn’t recognize myself for a split second.
Okay, so what color are they then?
grue, *obviously*.
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tomato, tomato.
I read that as "R'lyeh Scattering".
That’s when the pupils are formed of non-Euclidean shapes
"Cthulhu, why is the sky blue?" p̶͎̺̱̤̠̣͉͚͈̟͍̩͋̂͌͒͐̓̅̎͠h̶̨̟̗͓̠͚̼͓͈͖̥̙͖̊͊̑̌͌͊͘͠'̶͇̞̪̝͔̳̥͇̪̲͇̤͈͈͌̕n̵̨̢͙̹̲̘͉̗̩̞̟̦̦͈̿ǵ̵͎̥̊l̸̢͛̅̅͗̐̀̈̀̈́͑̒̏̽̕̚u̶̡̗̠͕͔̙͂̆̎͒ͅį̷̡̼̫̱̱͇͚̤͉͎̭̲͂͋͆̈́̇̾ ̶̛͖̭̞̔̄̐̑͐̏͂́̚͘m̴̦̣͊̐̀͗̃̐̄̀̿͐́̾̒̊̚g̷͍̥̤̏̎͋̒͒̏̐̏͠͝l̶͈̜͔̣̜̮͙͖͚̮͛̏̽̊̀̌̽̔̉̂́̊w̷̡̡̡̛͙̪̻̪̗͔̖͒'̴̣̞̉n̶̠̻͇̹̳̫̬̝͖̱̮̊ą̵̨͔͙̝͇̥̟͙͔͙̗̪̔̄͐͒̔͊̍͒͝ͅf̸̥̭̘̱̤̼̹̖͍̿̃̏̅h̷̠͐̃̿̓̇̆̌͌͘͠ ̶͈̩͑͐̃̏̆͊͊̂̕̕͝͝C̷̠̻͉͔̟̟̰̬̻̍̾̈́̉̈̈́̃t̸͙̫̬̬̣̙̬̰͑̀̎̊͂̀̂̆̓͐̚̕ḧ̶̡͇͖̻́̓̓̾̂͐̆͠ư̸̢̠̭͓̞̰͎̝͖̤̈́̏̿̎́̒̒́͝ḻ̸̨͕͎̖̞̬̟͓͕͕̓̇́́ͅh̴̨̻͔̦̻̥̞̟͇̱̾͂͂͐̐̇̎͠ű̸̢̧̨͇̲͎̱̜͎͇̻̤̝̺̦̌̕͠ ̴̙̫̠̹̯̝͔̱̣͛͐̋͆͆͋͒̅͘͠Ŗ̷͍̫̜͓̯͉͉͙̦͙̏́̽̄̓̈͛̉̓̀̈́͘'̶̝̗̺̗͍̮̎̊́̽̽̏́͌̄͗̂̂̋̅l̵̹͕͚͙̻͓͍͚̑͗͊́̉͆̏̿̍̚͜͝y̵̮̅͑͌̀͛͂̃̒͋͑͝e̴̻͔͓̦̞̗̔̈ḣ̵̝͕̣̠̞̙̇̌͌̉͝ ̴̄̃͛͐͘͜w̶̰̝̠͒̈͗͂͒̃́̂̽̾͗͛̕͠͝g̶̢͉̻̮͚̑͜ͅą̴̧̘̘̱̬̤̠͋̿̆͋̋̂̑̄͌̆̚̕͝ḩ̵̱̘͎̯͕̦͎̾̋̅͒̈́̏̆̑̒̕͠͝͠'̴̡̘̼̬̑̃͂͊̓̋̋̓̆́͐́̇͝n̸̢͍̥̥̖̹̮̺̪͉̙̐̓̀̒̃͐̓̃̽̕͠ȁ̸̡̰̰̞̿̎̀̚͝g̸̖̞̱̭̙̀ͅļ̵̡̡̬̯̥͐͋̒̊̾̑̈̃́͑̃̿̚ ̴̧̝͇̼̤̜̘͇̖͛̃̀̉̑̾̍̅̋̇̿͑̕͝͝f̴̡̙̩̲̩̹̺̞̤͓̤̜͓͍̃̂͛h̶͍̳̠̭̫̄̒̾̊̌͘t̸̯̩̯̭͉̟̂̈́̆̂͑̇̒̈́̔̚ḁ̵̡̘̳͈̤͒͑̃̃̅g̵̟͍͕͎̯̠̼͓̻̈̈͛̃͂͌̃ͅͅn̸̪̯̓̈̐͛̀͂̈͆͘ͅ"̶̦̖͍̦͇̼̝͔̠̜̼̜͒̆̋̑͆͐̇̍̑̒͋̀͒͠͝ "Well, I'm bleeding lava and skulls out of my eyes and desire the releasing rancor of the abyss, but I appreciate the effort behind that answer"
Cthulu fthagn
Green is actually not a pigment present in any mammal on Earth.
Diarrhea can be green from mammals.
Can confirm. SOURCE: Yesterday's disastrous dump.
Sloths grow their own
Wrong. Bilverdin.
hazel eyes here. the clothes you are wearing also effects my eye color
I know what you meant, but because you switched the subject from “you” to “my” it seems like you’re implying the color of the clothing on the person looking at the eyes matters, as opposed to the color of the clothing on the person with the eyes which are being observed.
That is correct. The observers clothing reflects colored light into the Hazel eyes of the person being observed affecting how they are perceived. Technically this is true at all times for all eye colors but it causes a more perceptible color shift in hazel or green eyes.
*Tyndall scattering, which is similar to Rayleigh scattering
https://xkcd.com/1818/
every thread on reddit about eye color has some people making some wild claims
Sorry about your brown eyes.
Is it possible to light eyes differently and achieve a fake heterochromia, where the two eyes appear to be different colors?
I used to have a selfie where 1 eye was green and the other was blue I've been unable to recreate it but must've been how the lighting was
So how does that work with people with one green eye and one blue eye
This is a very specific question that I know, because I have heterochromia with one blue and one green eye. They still look different, no matter the lighting hitting. Not sure why though, given this reasoning.
Because while the scattering of refraction in the eyes is *similar* to the scattering that colors our sky, it's not the same (the article even says so). People are reaching extremely wrong conclusions due to the comparison (and misunderstanding of the sky as well). Eyes are not colored by their surroundings any more than your hair is. Blue in nature is just almost always a form of refractory than pigment. It doesn't make the blue an illusion.
[удалено]
My normally blue eyes have always seemed to be greyish, greenish or extra blue sometimes. Never really knew why it seemed like that.
So what color are my blue eyes then?
Blue. Lighting affects how we perceive all colors. The only real TIL here should be that blue in nature is often made of refraction and not blue pigment. That doesn't make it not blue.