Is there a scientific reason for Asian peoples eyes?

I was curious if there is a reason that Asian people have (for lack of a better word ) squinty eyes. I know that many races of humans evolved a specific way to better suit their environment. But i cannot see the reason for Asians to have eyes like that.

Has this been figured out by Scientists?

Another good question could be why are other peoples eyes round.

But that is a good question about the asian eyes. Why are they like that?

Originally posted by earth2
Another good question could be why are other peoples eyes round.

But that is a good question about the asian eyes. Why are they like that?

Well 99% of mammals eyes are round (just guessing). So the Asians are the huge minority.

I remember reading somewhere that it had to do with the glare of the sun off the flat steppes of Asia. Their eyes are more 'squinty' to block out more direct rays of sun. This theory could be completely wrong, but its seems to at least have some intuitive merit.

First of all, is it possible to use the proper term? Epicanthic fold.

I've heard it's because of glare, and also to help keep out blowing sand. I did a bit of poking around to research it, but it is apparently not a burning question for scientists.

Seems like the desert people would have the squinty eyes before the asians.

I think it has something to do with being isolated for long long time with no outside genetic mixing.

edit: sorry I meant Epicanthic fold

[edit on 18-7-2007 by earth2]

Originally posted by earth2
Seems like the desert people would have the squinty eyes before the asians.

I think it has something to do with being isolated for long long time with no outside genetic mixing.

edit: sorry I meant Epicanthic fold

[edit on 18-7-2007 by earth2]

Yeah, then why dont all desert people have Epicanthic folds?

And i think we all could use them if they are so great at blocking out the sun.

I dont think we have an answer yet.

I found a couple reasons on yahoo answers,

Other races have slanted eyes too, though it's less common. The effect is caused by loose skin called an epicanthic fold. I'm assuming it's a climatic adaption, probably to a snow covered environment because slanted eyes would be less exposed to the glare off the snow. The pale skin that a lot of asians have would also suggest adaption to a cloudy and probably colder environment. Certainly the coldest regions on earth often have mongoloids as an indigenous population.

By the way, I am Asian and I don't have slanted eyes. And besides, it looks unique and distinguishes our race from others.

Asian eyes vary because they are adapted to different climates. In the cold climate of the Far East, Far East Asians have more fat on their eyelids which causes an inner eyelid fold. This fat warms the eyes, conserving body heat. Conversely, in the hot climates of Southeast Asia and the Indian Subcontinent Asians have eyes adapted to heat. These eyes have limited fat above their eyes. This makes their eyeballs look sunken into their skull and the spherical shape of their eyes to stand out clearly.

[edit on 18-7-2007 by earth2]

[edit on 18-7-2007 by earth2]

Some features, however, have no known use. Take vestigal bones in whales.
It could be the same with Asian eyes.

Originally posted by hikix
I was curious if there is a reason that Asian people have (for lack of a better word ) squinty eyes. I know that many races of humans evolved a specific way to better suit their environment. But i cannot see the reason for Asians to have eyes like that.

Has this been figured out by Scientists?

The epicanthic fold is a good screen against harsh sunlight, such as that encountered in a snow-covered environment found during many of the previous Ice Ages. It's not only found in East Asian folk. Laplanders, for instance, have the same thing.

I had always heard that the epicanthic fold was a feature of Inuit Peoples. It seems that the 'double eye-lid' offered some protection against the glare of the snow. This might explain the presence of the epicanthic fold in Asians -- especially the Asian peoples in the higher altitudes; i.e. Tibet. Nevertheless, the fold is to be found in a number of peoples including people in Eastern European who are not, necessarily, considered Asian, but it does raise the term Eurasian.

Anyway, Wikipedia has a few things to say about the epicanthic fold worth reading. I found it interesting to note that Native Americans, Finlands' Sami peoples and the Inuit have the fold which would join nicely with numerous Land Bridge Theories of migration.

Dont Eskimos have the same fold? I dont think its for the sun.... Well who knows they are the oldest civilization of people to roam the earth arent they oh well just guessing because I havent researched that just from what Im remembering from txt books lol. That is an interesting question though never really put much thought into it.

Originally posted by M4K4V3LI
Dont Eskimos have the same fold? I dont think its for the sun.... Well who knows they are the oldest civilization of people to roam the earth arent they oh well just guessing because I havent researched that just from what Im remembering from txt books lol. That is an interesting question though never really put much thought into it.

Have you ever seen snow goggles before? Perhaps the epicanthic fold operates off of the same principle.

Asians are not the only ones with epicanthic folds, the capoid people in Africa have them. A number of southern Africans have them.

[edit on 18-7-2007 by Amelie]

Originally posted by uberarcanist
Some features, however, have no known use. Take vestigal bones in whales.
It could be the same with Asian eyes.

Vestigial bones in whales' flippers and tails are there simply because the whales adapted to the sea from the land. The number of bones doesn't vary much among all mammals. For instance, a giraffe and a homonid have the same number of neck vertebrae, the giraffe's are simply very long versions of ours.

The eyelids of Asians, and others' that developed in cold climates, are new adaptions and, therefore useful. This is the opposite of the somewhat obsolete bone structure of a whale's flippers.

Mixed-up Asians

Originally posted by earth2
I think it has something to do with being isolated for long long time with no outside genetic mixing.

Why do you think East Asians (West and South Asians have no epicanthic folds) were isolated for a long long time?

East Asia is part of the largest continent, Eurasia. Overland migration north of the Himalayas was never all that hard. East Asia also has a very long coastline and the surrounding seas are shallow and easy to navigate.

East Asia has seen plenty of immigration and emigration. The Chinese were so plagued by invaders from the west they built a Great Wall to keep them out. It didn't work so well; the Mongols bribed a Ming general to open some gates and overran China anyway -- after which they interbred with the natives until they became natives themselves. Since the Mongol Empire reached all the way to the gates of Vienna at one point, there was plenty of opportunity for cultural and genetic cross-fertilization.

Two of the world's largest language families, Austronesian and Sino-Tibetan, originated in prehistoric East Asia and dispersed from there over a pretty big chunk of the world. Austronesian, originating in South China or Taiwan, spread throughout Southeast Asia and all across the Pacific ocean to Hawaii. It also spread westward across the Indian Ocean to Madagascar. Sino-Tibetan speakers occupied China, Tibet and much of Central Asia. Between them, these two language families count more native speakers than the most widely distributed language group, Indo-European (the group that includes English).

The origins of the Japanese and Korean languages are obscure and controversial, but both have vocabularies heavily influenced by other languages, showing that the people who spoke them were exposed to many outside cultural influences, and doubtless genetic ones as well.

Malays and Khmers are obviously not the same, genetically speaking, as Chinese; they have darker skins and other characteristics that seem to show interbreeding with other peoples such as Indians and Chinese, as well as with each other. Yet both groups possess epicanthic folds.

Imperial Chinese navigators had the Indian Ocean basin pretty well covered by the early years of the fifteenth century. They reached both Arabia and East Africa in the early 1400s. See this Wikipedia article on the voyages of Zheng He (Cheng Ho), the famous Chinese eunuch-admiral.

The Chinese, in particular, have always been great travellers and remain so to this day. If there is a big city somewhere in the world that doesn't boast a Chinese restaurant, I have never heard of it.

Genetically isolated? I don't think so.

In the world today, everybody is a mongrel.

One possible reason for such differences is simply that at some point in time, the men of a tribe decided that - for example - women with almond shaped eyes were more attractive. Such women were more likely to have children. Such children were more likely to have almond eyes ..... and over the generations it becomes the norm.

In other words, selective breeding - just as we do with domestic animals.

Originally posted by hikix
I was curious if there is a reason that Asian people have (for lack of a better word ) squinty eyes. I know that many races of humans evolved a specific way to better suit their environment. But i cannot see the reason for Asians to have eyes like that.

Has this been figured out by Scientists?

I don't know but this is interesting, and might add some dimension to the topic.


First Europeans Came From Asia, Not Africa, Tooth Study Suggests
news.nationalgeographic.com...

Europe's first early human colonizers were from Asia, not Africa, a new analysis of more than 5,000 ancient teeth suggests.

But the shapes of teeth from a number of hominid species suggest that arrivals from Asia played a greater role in colonizing Europe than hominids direct from Africa.

Originally posted by SuicideVirus
The epicanthic fold is a good screen against harsh sunlight, such as that encountered in a snow-covered environment found during many of the previous Ice Ages. It's not only found in East Asian folk. Laplanders, for instance, have the same thing.

Well then that makes me very curious about people like Scandinavians, Finland. They experiences snow as much or more than most Asian countries, Korea etc..
Yet they do not have Squint-Eyed Syndrome. also as has been mentioned, the desert dwellers dont have this issue either. good question though..



[edit on 8/9/2007 by Kr0n0s]