Blue Light affects your brain...may explain some things on Pandora

Started by Seze Mune, February 21, 2012, 10:21:22 PM

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Seze Mune



As everyone here knows, James Cameron specifically designed Avatar with the color cyan in mind.  I remember reading somewhere that after watching the original footage, they decided to add in reds and greens to balance the color, but cyan-blues are a dominant color scheme and even mentioned several times in the script.

Cyan seems to run the gamut from a periwinkle to a greenish teal as in the above square. Cameron mentioned the colors cyan-blue and periwinkle several times, so I think his mind drifted toward the blue end of the spectrum.

It turns out that blue is an important color.  Within human eyes - even if they're blind - lie blue photoreceptors we're only just beginning to learn about.  Blue light is particularly effective at setting the circadian rhythm in organisms, and not just mammals.  It is also a powerful mood regulator, perhaps even better than white light for treating Seasonal Affective Disorder.  Blue light elevates body temperature and heart rate and reduces sleepiness, contrary to what you might expect.  Blue lights seem to help memory too, as well as boosting your ability to respond to sound and stay alert.  Bulimia and anxiety might be beneficially affected by short wavelength blue light.

HOWEVER, much research remains to be done because certain blue lights can increase damage to eyes.  Many light emitting diode type lights are blue-saturated, and these might lead to macular degeneration, a leading cause of disability in older people.  It's possible that as we switch to these more efficient types of blue-enhanced light, that we will see this disability appear in much younger people.

AS FAR AS AVATAR IS CONCERNED, I have read criticisms that the Na'vi eyes are too big and lemur-like to be scientifically plausible. Considering the densely shadowed rainforest in which they live, and the amount of ambient blue in their environment, along with what ophthalmic science is beginning to discover about the interaction between eyes, light, color and brain response, it seems intuitively evident at least that there is a case to be made for the size (and perhaps even the color, as yellow is the complement of blue) of their eyes.

My coupla pennies, anyway.  ;)  Thoughts, anyone?

What's in a Color? The Unique Human Health Effects of Blue Light

Vision Science: Seeing without seeing

Niri Te

 That is a great post ma tsmuke, I wonder if for people suffering from SAD, if a light positioned in such a manner as to not be able to be viewed directly, and not a high intensity LED array, with a blue filter in front of it, allowing the entire room of said person to be bathed in a SOFT blue light, might be therapeutic, without causing serious eye problems?
THIS is a subject for Scientific, and Medical research I believe.
ta Niri Te
Tokx alu tawtute, Tirea Le Na'vi

Meuiama Tsamsiyu (Toruk Makto)

Let's not forget those horrid halogen headlights. You practically have to stop when you encounter an oncoming set... so blinding, completely.

As for the yellow eyes of the Na'vi. Wouldn't that change their visual perception altogether like a cat or dog or many other animals?

Personally, I like the size of their eyes. Eyes are a doorway into the soul and speak volumes... and you canr eally see the way of the Na'vi in them... as well as the ears and tail LOL



"He who destroys a good book kills reason itself." -John Milton

"Mathematics is the gate and key to the sciences." -Roger Bacon

"There is only one good, knowledge, and one evil, ignorance." -Socrates

Alyara Arati

Having yellow eyes is a function of what pigment molecules, and how many, are found in the iris of the eye; the iris functions as a shutter, to control the amount of light coming through the eye to the retina, but its pigmentation is not related to sight.  Cats can have yellow eyes, but have almost no color vision; however hawks with yellow eyes see incredibly well during the day, but very poorly at night.

An interesting (to me) side note is that in WW2 the Navy experimented with using blue light displays and ambient light at night instead of red for some of the same reasons listed in the original post.  Unfortunately, blue light, having a short wavelength, travels the farthest and gave away the ships' positions too well, so they quite quickly changed back to the standard red night lighting.
Learn how to see.  Realize that everything connects to everything else.
~ Leonardo da Vinci

Seze Mune

Quote from: Alyara Arati on February 22, 2012, 05:40:19 AM
Having yellow eyes is a function of what pigment molecules, and how many, are found in the iris of the eye; the iris functions as a shutter, to control the amount of light coming through the eye to the retina, but its pigmentation is not related to sight.  Cats can have yellow eyes, but have almost no color vision; however hawks with yellow eyes see incredibly well during the day, but very poorly at night.

An interesting (to me) side note is that in WW2 the Navy experimented with using blue light displays and ambient light at night instead of red for some of the same reasons listed in the original post.  Unfortunately, blue light, having a short wavelength, travels the farthest and gave away the ships' positions too well, so they quite quickly changed back to the standard red night lighting.

Very interesting information, ma tsmuke.  Especially about the warships and blue light duirng WW2.

As for the eyes, it made me do a little research.  It's a common assumption that melanin seems to be produced in greater quantity as an effect of the human body's response to the sun, e.g. black people with deep brown eyes developed in equatorial regions whereas blue-eyed blonde types seem to have evolved in sub-Arctic regions. So goes the hypothesis.  

I have read that some people refute that by saying that if it was a function of sunlight, deer and other animals would also have developed blue eyes and that does not seem to be the case. In actual fact, there are deer with blue eyes, though I have no idea whether they are more common in Scandinavia than in the southern US or South America:



Regardless, animal eyes actually function differently from human eyes and are sensitive to different radiations of light than ours are, so the refutation is built on comparing oranges to apples.

Melanin plays a role in iris coloration as it does in skin pigmentation.  The iris is made up of two layers, both of which employ melanin for color.  The function of the pigmentation, according to ophthalmic sources, is to block light from passing through the iris, funneling it through the pupil instead. These colored layers are connected to two sets of muscles which contract the pupil in a circular motion and also radially, pulling the iris back in folds.  It is interesting to speculate that the iris itself has some reactivity to light and helps to mediate its own dilation, and is not just the effect of light striking the retina.  

There is a study which indicated there was a difference in visual acuity depending on the amount of pigmentation in the iris as evidenced by its color, and the study formed a further hypothesis that varying densities of melanin pigmentation were formed as an adaptation to the well-known property of heat absorption of the melanin granules.  I did not have the proper credentials to access the complete study, unfortunately.

It is also interesting to note there is a statistically significant relationship between iris pigmentation (i.e. melanin expression), and rates of macular degeneration, at least in the US.  Macular degeneration is a disease of the retina and its specific causes are still under scrutiny.  

Also, there is a relationship between eye pigmentation and diseases of voluntary movement (dystonias).  Speculation has it related to metabolic processes which also result in the production of melanin, but no one knows that for sure.So in effect, there is some evidence for a relationship between iris color and the acuity of eyesight on several levels.



Na'vi eyes, being both large and light-colored, may lend to speculation that they are sensitive to extra-human light spectra.  Only avatars could give us that feedback and unfortunately it was not addressed in the movie.  The ikrans are supposed to have one set of eyes which see in infrared, and one which see other spectra.  Perhaps it takes only one set of Na'vi eyes to be as sensitive as two sets of ikran, sturmbeest, toruk, or titanothere eyes?

Kamean

Tse'a ngal ke'ut a krr fra'uti kame.


Meuiama Tsamsiyu (Toruk Makto)

Quote from: Alyara Arati on February 22, 2012, 05:40:19 AM
Having yellow eyes is a function of what pigment molecules, and how many, are found in the iris of the eye; the iris functions as a shutter, to control the amount of light coming through the eye to the retina, but its pigmentation is not related to sight.  Cats can have yellow eyes, but have almost no color vision; however hawks with yellow eyes see incredibly well during the day, but very poorly at night.

An interesting (to me) side note is that in WW2 the Navy experimented with using blue light displays and ambient light at night instead of red for some of the same reasons listed in the original post.  Unfortunately, blue light, having a short wavelength, travels the farthest and gave away the ships' positions too well, so they quite quickly changed back to the standard red night lighting.

I m certainly well aware of the red, with which one can barely see unless their eyes are attuned to the darkness involved... or know their way around the room or passage. I spent around half my fleet career as a Marine on the water afloat in Navy ships USS Saipan and USS Bataan, also did workups before completing my four years as a Marine on the USS Iwo Jima.

Learned not to starch our cammies for presentation if we were going to the field in a certain amount of time from that point cause the starch actually enhances and reflection of any light... 'moon'

Also learned that even the cherry of a cigarette can been seen by night vision from over six miles away. Those things I guess really CAN kill you. Or get you killed. LOL



"He who destroys a good book kills reason itself." -John Milton

"Mathematics is the gate and key to the sciences." -Roger Bacon

"There is only one good, knowledge, and one evil, ignorance." -Socrates

`Eylan Ayfalulukanä

I love blue light, and was thilled when blue LEDs began to becom common. I like deep blues and violets, and seek out LEDs with the 430 nm or so color. This wavelength is sometimes called 'royal blue', and is often used to excite 'remote phosphors' in modern LED lamps. (That color light, in too great a quantity though, can hurt the eye.) I have some violet LEDs that are available through popular hobbyist/replacement semiconductior manufacturer NTE. They are really pretty. I also have a couple of UV LEDs that I have experimented with. UV LEDs are getting more and more common.

The blue light navy experiment is very interesting. Blue light, I would think, would disturb night vision more. Although I like the ambiance of blue light, I find it hard to work under. (Might be my lousy blue eyes) Red light is what everyone working in astronomy uses. And in fact, at major star parties, you will get a stern warning if you use any other color of light.

Blue eyes in animals is often associated with leuicism (may not be the right spelling), which is the condition that gives us white lions and tigers. The deer pictured, most likely a fallow deer who frequently come in white, is most likely exhibiting leuicism. Leuicism is considered a rare but normal coloration in the big cats, and is different from albinism, which is a complete lack of pigment (and is usually considered abnormal). Animals with albinism tend to have pink eyes. I will check our white fallow deer next time I am at the zoo, and see what color eyes they have.

Yawey ngahu!
pamrel si ro [email protected]

Seze Mune

Ma 'Eylan, I have never heard of leucism before.  It fascinates me. If I understand the difference between it and albinism, with leucism ALL pigment cells are reduced in production of pigment, whereas in albinism, only the melanocytes or melanin-producing cells have reduced production.  Not all species carry all types of pigment producing cells, so the result can be different looking in different animals.  For example, certain albinistic animals might not produce much melanin, but if they harbor other pigment producing cells they might take on a pale color.  It also tends to leave eye color intact.

What I wonder is whether there is a relationship between the pigmented retinal cells and leucism, so that animals which have this trait are more prone to vision defects despite the normal color of their eyes.  One of the problems with macular degeneration is the yellow pigment at the back of the retina (on the fovea) which begins to bleach and atrophy, especially in the presence of 'high energy' blue light.  As it does, vision loses sharp distinction and color, tending to shroud everything with a dense gray cloud.  Often there are deposits of drusen which are bits of extracellular material which should be removed as waste products but for some reason drift behind the retina and stay instead.

Seze Mune

This also makes me wonder: if normal incandescent lighting is yellowish, then where is computer light on the spectrum....does it have one underlying color or is it just dependent on the colors on the monitor?

Meuiama Tsamsiyu (Toruk Makto)

Your range in knowledge astounds me, ma Seze. Yer another topic that you seem to excel in where I do not LOL



"He who destroys a good book kills reason itself." -John Milton

"Mathematics is the gate and key to the sciences." -Roger Bacon

"There is only one good, knowledge, and one evil, ignorance." -Socrates

Seze Mune

I am a dilettante, ma Toruk.  I know a very little bit about a wide range of subjects - just enough to get myself in trouble.  But at least I have fun doing it.    :D

`Eylan Ayfalulukanä

Quote from: Seze Mune on February 22, 2012, 10:53:10 PM
This also makes me wonder: if normal incandescent lighting is yellowish, then where is computer light on the spectrum....does it have one underlying color or is it just dependent on the colors on the monitor?

Computer displays, and any kind of video display in general, produce three colors of light: red, green, and blue. Although not truly monochromatic colors, they are still narrowband enough to be quite pure. These colors are combined to produce all the colors we can see on displays.

Incandescent light is very broadband in spectrum. This is why it is pleasing to people. Almost all other lighting is monochromatic (high pressure sodium) or has multiple individual colors of light mixed together (fluorescent, metal halide, white LED, etc.) This kind of light bothers some people. (I really like classic linear fluorescent light, especially the now high color-rendering-index (CRI) whites. I strongly prefer this over incandescent, except tor the high color temperature quartz lighting (3200K) typical of stage/TV lighting.)

Yawey ngahu!
pamrel si ro [email protected]

Ateyo Te Syaksyuk

OK I am terrified of macular degeneration.  Cataracts runs in my family too.
Most of the lighting in my home is either LED, the soft warm glow of the propane heater, my ever present laptop andvery indirect sunlight.  Short of staring into oncoming headlights, I don't think I am in any danger of damaging my eyesight. (someone's grill, pehaps)
And the otherhand, I like the Christmas decorations in which an entire tree or house is covered in blue.  It makes me go OOH AH
Hospitals seem to think their version of green is soothing.  They must have read it somewhere.  I haven't seen many interiors painted that way lately.  Maybe someone was running a sale of bland green paint in the 60's,
I'm blathering now.  I'll shut up!

Niri Te

 The reason for that color green, is that it doesn't show up blood stains.
Tokx alu tawtute, Tirea Le Na'vi

Niri Te

 If what they are saying about the wavelength of blue light having a probable causative effect on macular degeneration, holds water, then that only makes night time red lights all the more attractive.
Niri te
Tokx alu tawtute, Tirea Le Na'vi

Seze Mune

Lots of research is being done on macular degeneration.  Stem cell therapy holds much promise.  In the meantime, the best things to do are to protect your eyes from UV light by using sunglasses, and make sure that you add certain vegetables and fruits daily to your diet:

"FACTS:

    "People who eat a diet high in vegetables and fruit have a lower incidence of age-related macular degeneration.  Dark green, leafy vegetables are particularly helpful.
    People who eat fish three times a week have a lower incidence of macular degeneration.
    People who eat a lot of saturated fats have a higher risk of AMD.

Eat Lots of Vegetables and Fruits


Antioxidants protect against oxidation, which is a part of the process of AMD.  Dark green leafy vegetables like spinach, kale, mustard greens and collard greens contain high levels of lutein, a critical antioxidant. Antioxidants are also present in fruits and vegetables with bright color, including red grapes, peppers, corn, oranges, cantaloupe and mango. Look for fresh produce in a variety of colors to get a wide range of vitamins in your diet.  We don't have all the answers, so eating a varied diet is wise.

Eat 5-9 servings a day. While this may sound like a lot, a serving is really only ½ cup of most foods or one cup of leafy greens.

Eat Fish

People who eat fish 2-3 times a week have a lower risk for AMD. Fish contain omega-3 which seems to be a critical nutrient for the heart and eyes. The best fish are either wild salmon or small fish like sardines. If you cannot tolerate fish or obtain it easily, an omega-3 supplement is another option. Fish oil capsules are widely available.

Limit Your Fat Intake

In reviewing studies on fat, researchers found that while the amount of fat consumed makes a difference, the real issue for AMD is the amount of saturated fats in the diet.

The biggest source of saturated fat is animal products - beef, lamb, pork, lard, butter, cream, whole milk and high fat cheese. Plant oils also have saturated fat, including coconut oil, cocoa butter, palm oil and palm kernel oil.

Read the labels on processed foods and baked goods, as they often have high amounts of saturated fats."

Ateyo Te Syaksyuk

Granny was right! Eat your veggies! Guess I had better cut back on butter.  I am trying to wean myself of prepackaged foods.  It is hard to do with out refrigeration! In the desert!

Meuiama Tsamsiyu (Toruk Makto)

I am always learning new things from you, ma Seze. I also agree with the fish and the vegetables. Glad I like both :)



"He who destroys a good book kills reason itself." -John Milton

"Mathematics is the gate and key to the sciences." -Roger Bacon

"There is only one good, knowledge, and one evil, ignorance." -Socrates

Seze Mune

Thank you ma Toruk.  This info and more is easily available on the internet.  Glad I don't live in Egypt, China or Iran these days considering what they're doing with the internet.