What Are Blue Eyes Good For?
- Pieter Maas
Advantages of Blue Eyes – A big advantage to blue eyes is that research shows they might be linked to a lower risk of developing cataracts. Cataracts are clouding of the eye’s lens. According to some studies, blue eyes may have evolved because these individuals were able to cope better with seasonal affective disorders.
What is the purpose of the blue eye?
Tell us about the history of the evil eye. – A quasi-universal symbol of protection, the evil eye is referred to as μάτι ( mati ) in Greek. The concept and the significance of the evil eye is especially prominent in the Mediterranean and West Asia. The evil eye is a “look” or “stare” that is believed to bring bad luck for the person at whom it is directed for reasons of envy or dislike.
The perception of the nature of the phenomenon, its causes, and possible protective measures, varies between tribes and cultures. The evil eye is a talisman that is meant to protect you from these evil spirits. The evil eye is a ‘look’ or ‘stare’ believed to bring bad luck for the person at whom it is directed Belief in the evil eye—”mati”—dates back to Greek Classical antiquity, to at least the 6 th century B.C.
when it appeared on drinking vessels. It is referenced by Plato, Hesiod, Plutarch and many more classical authors who attempted both to describe and explain the function of the evil eye. Plutarch’s scientific explanation stated that the eyes were the chief, if not sole, source of the deadly rays that were supposed to spring up like poisoned darts from the inner recesses of a person possessing the evil eye.
It is a curse or legend believed to be cast by this malevolent glare, and usually given to a person when they are unaware. An evil eye is a talisman or amulet, designed in the shape of an eye, traditionally in the colors blue or green, that indicate spiritual protection. These talismans or evil eye “repellents” come in different shapes and forms as pendants, bracelets, earrings and rings.
Or can be hanging in a glass bead form over the main door or entrance of someone’s home to keep the hearth protected.
What eye color is the most beneficial?
Do Different Eye Colors Have Different Benefits? – Because of the sometimes simplified way concepts like genetics and Darwinism are taught, we might reasonably assume there is a survival-based reason various eye colors developed and survived in various human populations.
Reduced risk of macular degeneration Lower melanoma risk
Lighter eyes may have some advantages too, but they are also linked to certain health and addiction risks. People with lighter eyes may have the following:
A lower chance of developing vitiligo A higher risk of abusing alcohol Greater light sensitivity, especially among people with albinism
Notably, the potential differences in health impacts between different eye colors are almost certainly slight. The reason different eye colors have managed to survive is largely because they didn’t significantly impact the survivability of the early humans who developed them.
Why are blue eyes so pretty?
The Healthy Journal – Gluten, Dairy, Sugar Free Recipes, Interviews and Health Articles People consider blue eyes attractive, but in reality, blue is rated as attractive as other iridal colors. Bright scleral color and large pupils positively affect attractiveness because both features are significantly correlated with youthfulness, |
Why can blue eyes see better in the dark?
Adjusting to Darkness: How Our Eyes See at Night It’s escaped no one’s attention that this year’s name is also the term for sharp vision—2020. So let’s check out your vision in the sky! Plus, here are some fun facts about how long it takes for our eyes to adjust to darkness and whether your night vision is affected by your eye color.
- The human eye is amazing and uses different modes to see during the daytime and to see at night, and can also Living in Full Color: Photopic Vision People who move from a city into a rural area are often spooked by the darkness.
- City streetlights provide enough brightness to let our retina’s cone-shaped cells operate.
This yields “photopic vision” which lets people see sharply, and in color. Seeing in the Dark: Scotopic Vision But at night in the country, we only get to use our rod-shaped cells, which bestows scotopic vision. Scotopic kicks in when things are dim, but its not a great way to perceive the world.
First off, rods are colorblind. Next, there’s not a single rod lurking in the middle one degree of vision; So in low light situations we suffer a one degree blind spot straight ahead, twice the size of the moon. (There’s also a second, better known blind spot present in bright light. But this one’s off to the side, and we don’t usually notice it: If an object is hidden at the blind spot of one eye it will be seen by the other.) Another quirk of rods is that they’re very slow-acting, which is why night sensitivity takes at least 5 minutes. When you first switch off your bedroom lights, you probably see nothing at all. After a few minutes, things in the room become obvious. On top of all these failings, scotopic vision only delivers 20/200, ten times less sharp than photopic vision. You’ve always sensed the truth of this. Sharp details (like the creases in that shirt you tossed onto the chair), which are so obvious when the lights are on, now become a blur in the dim light. We’re so accustomed to it, we probably associate dimness with vagueness. But it’s those darn rods again.
This is why beginners who buy telescopes are sometimes appalled at how few details appear on galaxies and nebulae, on top of them being colorless. This is why astrophotography is so important: it brings out stuff the human eye would simply never see, even through the largest telescopes.
Combining Both: Mesopic Vision Photopic vision and scotopic vision combine in low but not quite dark lighting situations. A full Moon gives just enough light to slightly get the cones going, while rods are still operating. This is called mesopic vision—both. Here, the cones operate only at their place of peak sensitivity, which happens to be blue-green.
That’s why the natural world in the country will appear that color under this month’s full moon. Suddenly, the night makes sense. A Few More Fun Facts about Night Vision
Can humans see in total darkness? Ever been in a cave when the lights are turned off? Now that’s dark! You can’t see anything—even your own finger in front of your face. Humans can see in the “dark” only if there is some starlight or, better, moonlight. Does eye color affect night sky vision ? According to some studies, there is a slight difference in vision capabilities based on eye color. Light-eyed people (with blue or green eyes) have slightly better night vision because they have less pigment in the iris, which which leaves the iris more translucent and lets more light into the eye. However, dark-eyed people tend to see better in bright sunlight and are less susceptible to glare, because darker irises act like a stronger filter for light. How long does it take to adjust to darkness ? It takes some time (20 to 45 minutes) for your eyes to adapt to the night sky or light-light conditions. Best conditions are on a night with no clouds and a full moon (try it!). When dark adapted, you can see only in black and white (no color). If light hits your face, the dyes in your eyes “bleach” and then have recover their dark-adapted vision. That’s why astronomers get annoyed when someone carelessly shines a white light in their eyes.
Avoid using a bright flashlight at a star party. Some amateur astronomers use red LED lights to view things without ruining their night vision. Of course, this means your eyes have already adpted to the darkness. Some star gazers will put on a pair of sunglasses at least 20 to 30 minutes before venturing in the dark to adjust quickly. BONUS : You’ll also receive our free Beginner Gardening Guide! : Adjusting to Darkness: How Our Eyes See at Night
Who was first person with blue eyes?
Behind Blue Eyes: A Look at the Genetic and Cultural Components that Propelled the Spread of Blue-Eyed Humans
- This thoroughly-researched piece is by Sarah Henry, an instructor at Delaware County Community College and tour guide at the Mütter Museum.-KI
I have blue eyes and I have always been interested in exploring my own genetic origins, but I’m not the only one interested in this genetic trait. Countless songs and poems reference people with blue eyes, whether considered a mark of beauty, a representation of sadness, or, in certain cultures, a sign of the oppressor.
- But blue eyes, so popular in art, are relatively new in human evolution, as new as the invention of writing itself.
- My interest in this subject was sparked, in part, by a unique archaeological discovery; in 2006, researchers uncovered the world’s oldest confirmed blue-eyed person, dating to approximately 7,000 years ago.
This discovery helped to confirm theories regarding the familial relationship of nearly all blue-eyed individuals. This article will exam the genetic origins of blue eyes in humans, the spread of the blue-eyed gene, and the future of this genetic trait.
- Genetics: How Do They Work? The basic explanation of eye-color works like this: a person needs only one dominant brown-eyed gene (from one parent) to be brown-eyed but needs to have two recessive blue-eyed genes (one from each parent) to be blue-eyed.
- You have probably seen this explanation accompanied by a simple Punnet square (Image 1) in your science textbooks.
However, new studies illustrate that the genetics behind eye color are not so straightforward. There are actually two separate genes that control eye color in humans. In his article, “Blue Eye Color in Humans,” Hans Eiberg writes, “Blue/Brown eye-color are known to the public as a school example of inheritance of monogenetic inheritance, however, the variation in pigment concentration and the iris suggest the eye color genetics to be far more complex as supported by recent data.” In other words, eye color is controlled not by one gene passed from parent to offspring, but by two genes working in tandem; a more complex chart would take both of these genes into consideration (Image 2).
These genes are called OCA2 and HERC2 (represented as O, o, H and h in Image 2). The simplified explanation is that the OCA2 gene controls pigment in the stroma (the tissue and blood vessels) of the iris (the colored part of the eye around the pupil) and the HERC2 gene is needed to help turn on the OCA2 gene to cause it to produce this pigment, resulting in brown eyes.
- If a person has a non-functioning OCA2 gene, they will always have blue eyes, because the HERC2 gene can’t make the broken OCA2 gene work.
- Likewise, if a person has a HERC2 gene which doesn’t work, the OCA2 gene will “underachieve,” failing to produce enough pigment to make brown eyes, resulting in blue eyes.
These two genes aren’t directly related to each other, yet they affect each other. In this dependent relationship, both of these genes must work to give an individual brown eyes, a genetic relationship known as “epistasis.” Because of this process, it is actually possible (although rare) for two blue-eyed parents to have a brown-eyed child.
- How Do We Know All Blue-eyed People Are Related?
Homo sapiens (modern humans) emerged around 200,000 years ago in Africa, but the mutation that causes blue eyes did not appear until sometime around 10,000 years ago. In a study conducted by Professor Hans Eiberg and a team from the University of Copenhagen, researchers examined mitochondrial DNA from 155 blue-eyed subjects from Denmark, two from Jordan, five from Turkey, and 45 brown-eyed candidates, looking at the locus (specific location or position of a gene) responsible for brown or blue eyes.
The result was the discovery that more than 97% of blue-eyed people share the single H-1 haplotype (a group of genes within an organism that was inherited together from a single parent). Eiberg and his team write, “A shared haplotype among blue-eyed individuals is almost perfect and suggests the blue color phenotype is caused by a founder mutation.” This means that the vast majority of people with blue eyes share a single inherited genetic mutation, rather than each person with blue eyes possessing a unique mutation.
The study also tested seven blue-eyed Mediterranean individuals unrelated to the Danish participants as a control group. They, too, carried the H-1 haplotype. These individuals with the H-1 haplotype all inherited the same switch at the same location in their genetic coding, whereas, brown-eyed individuals have a number of variations in melanin production and DNA, with brown-eyed phenotypes being spread out between haplotypes H-5 and H-10.
- In short, almost all blue-eyed people came from a single ancestor, which is proven by the possession of the exact mutation at the same location in their genetic coding.
- That leads us back to the blue-eyed man from the article that sparked this entire investigation.
- Why is This Stone Age Body in Spain so Important? In 2006, researchers discovered a 7,000 year old body from the Stone Age in the La Brana cave system in Leon in Northern Spain (Image 4).
Genetic testing determined that this man had blue eyes. It was not in itself unusual, but what is remarkable is that he is the earliest known person with blue eyes. Far from being a fair-haired, far-skinned man that we may have expected, his genetics reveal he’s a mixture of other traits. In order to answer this question, we need to delve into Stone Age migratory patterns. According to Pickrell and Reich, there are two theories of cultural migration: Demographic Stasis vs. Demographic Change. In Demographic Stasis, inhabitants living in a particular region are the descendants of the first people to arrive in that region, meaning the people in a certain area were never integrated into or replaced by people from a second migration. Specifically, we can see this during the Neolithic (New Stone Age) Revolution, a period of time where humans began to cultivate crops, domesticate animals, and use polished stone tools. Prior to the Neolithic Revolution, almost all the world’s inhabitants subsisted primarily by hunting and gathering, but after the Neolithic Revolution, small pockets of farming emerged, first in the Fertile Crescent, China, and India and then spreading across Eurasia.
The Neolithic Revolution occurred between 6,000-10,000 years ago, and because people were better able to procure a steady source of food, the population increased significantly. The technologies which emerged during this time allow archaeologists and researchers to track cultural migration from the northwestern part of the Black Sea region (where the first humans with blue eyes lived) into the rest of Europe.
A study of Armenian haplotypes determined, “.hospitable climatic conditions and the key geographic position of the Armenian Highland suggest that it may have served as a conduit for several waves of expansion of the first agriculturalists from the Near East to Europe and the North Caucasus.” People migrated out of the Caucuses (modern-day Georgia, Azerbaijan, and Armenia) and into other parts of Europe (Image 6). Another study, focusing specifically on the genetics of residents of the Iberian Peninsula (excluding the Basques), indicates a mixture of genetic traits from the Caucuses, Central Asia and North Africa, probably related to migration during the Neolithic Era.
A study of eight Bronze Age individuals dated to between 5,500 and 3,500 years ago shows an admixture between existing hunter-gatherer groups and people from later migrations, meaning people who migrated to this area began to blend into the peoples that already lived there by blending both their culture and genetics.
Why Did this Recessive Genetic Trait Survive for Thousands of Years? How did the blue-eyed gene persist if there’s no overt evolutionary advantage to possessing it? One argument would be that those original groups of people who possessed blue eyes produced offspring with other blue-eyed people in their own group, leading to a population where blue eyes were the norm.
- However, there are both objective and subjective benefits to possessing blue eyes.
- Subjectively, possessing blue eyes may just make one individual more sexually attractive to another.
- Objectively, blue eyes filter light differently than dark eyes (dark eyes, like dark skin, possess more pigment which can protect those organs from sun damage), which make them especially advantageous in the low light of Northern European winters.
Because people with light eyes are more sensitive to light, they can see better in areas that lack sufficient sunlight for large portions of the year. Conversely, while light sensitivity (photophobia) proved useful in a world prior to electricity, it actually opens blue-eyed people up to a host of medical problems including an increased risk of macular degeneration, which can ultimately lead to blindness because light eyes are worse at filtering out harmful UV light.
- What is the future of blue eyes? At the turn of the 20 th century, 50 percent of people living in the United States had blue eyes.
- Now, however, people are more likely than ever to marry outside of their ethnic group, leading to more genetically diverse offspring and a decline in blue eyes due to the dominance of the brown-eyed genes.
Currently, in the U.S., only 17 percent of the population (1 in 6) has blue eyes and only between 5-8% of people worldwide possess the trait. (Green eyes are even more rare, but they are a topic for another article.) Even though they are new in human history, blue eyes are already on the decline.
Whether used to convey beauty, as one writer notes about the poetry of Longfellow and Romanticism, “It delighted in sentimental musings amid the ruins, in pathetic legend, in dreamy pictures of monks and harpers and knights and radiant maidens with soft blue eyes” or to convey sadness like in the Who song “Behind Blue Eyes,” where Roger Daltry sings, “No one knows what it’s like/ To be the bad man/ To be the sad man/ Behind blue eyes,” or as Kristina Richardson writes in her article regarding the perception of blue eyes in the Islamic Middle Ages, “My preliminary archival work suggests the Medieval Muslim male writers overwhelmingly accepted the characterization of blue and green eyes as unattractive and deviant,” a line of thinking fueled by the brutality of European crusaders who raped, pillaged and murdered in an attempt to reclaim the Holy Land.
Blue eyes have been a notable trait in literature across cultures for centuries. Though the future of blue eyes is unclear, nearly all living and dead blue-eyed individuals share a familial relationship through a single genetic mutation. If you have blue eyes or know someone with blue eyes, they are more than likely related to that 7,000 year old man whose remains that researchers found in a remote cave in Spain.
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Why are blue eyes better at night?
Blue eyes – This is the next most common eye color, encompassing about 10% of the population. While blue eyes are more sensitive to light during the day, people with blue eyes tend to see better at night – unless there are bright lights. In that case, the lack of melanin makes them as sensitive to light at night as they are during the day.