I swim like a dolphin and approach the reality of children who are "nomads of the sea"

Have no official nationality, Thai indigenous people who speak a unique language and live in the Indian OceanMoken tribeis. Children of the Moken tribe called "nomads of the sea" spend most of the day in the ocean to catch fish and sea cucumbers, but a certain Swedish scholar has learned that the mechanism of children's eyes of the Moken tribe to dolphins and seals I found out that it was similar and it became a big topic. "When the tide draws, the children swim out, but that's what I have never seen before.Their eyes are drawn deeply into the ocean floor, they are wide open, as if they were small dolphins "That's why the British news media BBC is approaching the secrets of children of the Moken tribe.

BBC - Future - The 'sea-nomad' children who see like dolphins
http://www.bbc.com/future/story/20160229-the-sea-nomad-children-who-see-like-dolphins

In the Andaman Islands of the Indian Ocean, the Moken tribe lives on a ship called "bag". The Moken tribe does not have official nationality and therefore can not receive public services such as medical care and education, but it keeps traditional customs and still lives hunting and fishing.


The recent survey revealed that children in the Moken tribe have different eyes from the children living on the continent. Since humans are usually optimized for living on the land, you can see clear images when you open your eyes in the air, but since the refractive index of the cornea is lost in the water, a blurry picture I can only see.

However, the Moken children can surprisingly reduce the size of the pupil even in the dark ocean, and can keep 1.0 eyesight even underwater. This is the same principle as making the focal length deeper by making the aperture of the camera small, making it easier to focus.


You can see how the children of Maken are swimming and how they are watching the sea world from the following movies.

How Moken children see with amazing clarity underwater - Inside the Human Body - BBC One - YouTube


Boys jumping from boat one after another.


Enter Savan and the sea ......


In the end it will dive deep into the bottom of the sea.


There is no equipment and a Mooken boy who swims sweetly and is nothing.


My eyes are wide open as if it is on land.


Normally, when a person dives in the sea with the naked eye, visibility blurs as follows.


However, children of the Moken family can surprisingly reduce their pupils ... ...


It is possible to see clear images like this.


It is easy to get prey.


The secret of sight of the Moken children is clarified by visual anthropologist Annah Gislen of Lund University of Sweden in 1999. Mr. Gislen actually visited the island where the Moken tribe lives and shared a living with them. Mr. Gislen said, "When the tides are full, the children of the Moken pop into the sea and dive deep into the sea, and they will catch clams, seashells, sea cucumbers, etc. for fishing, but at that time they The eyes of the eyes were firmly opened, and no problems seemed to have happened. " "That state was something I had never seen before, and those who dive into the ocean floor with firm eyes open are like little dolphins"


Mr. Gislen conducted some tests on children in the Moken family. The content of the test was to let the children face in the water, to show the cards with the lines written underwater, to have their face raised and ask the direction of the line to be answered. As a result of gradually increasing the difficulty level by narrowing the line, the Moken children are said to have recorded twice as good a test result as the children living in Europe.


First, Mr. Gislen who thought "The structure of the children's eyes is fundamentally different from theirs?", But the sight of the children of the Moken tribe on land is a child of Europe of the same age The hypothesis was unexpected because it was almost the same as those. Then the possibility of being left out is whether the Moken children can change the shape of the lens or reduce the pupil.

Mr. Gislen concludes that Moken children can contract the pupil even smaller than the size previously thought to be possible for humans. However, it is a view that the function of the crystalline lens is evolving in addition to the adjustment power of the pupil, because it can not explain the visual acuity of their pupils merely by pupil contraction. The mechanism that shrinks the pupil and changes the shape of the crystalline lens makes it possible to clearly see things in the water seems to be similar to the mechanism by which dolphins and seals see things.

Meanwhile, when Mr. Gislen conducted experiments similar to children for adults of the Moken tribe, it was found that adults had no particular eyesight in the water. This is believed to be the reason that the adult crystalline lens is less flexible than that of children. The adult Moken tribe who does not have amazing sight in the water, therefore he is hunting and preying the fish by fishing.


Because the ability is lost when becoming an adult, Mr. Gislen presumes that the extraordinary vision of the Moken tribe is not genetic, it was cultivated from two of children's abilities and training, the same age European children also had training to see things in the water. When I had the training to observe the written cards in the water and answer the direction repeatedly for one month and eleven sessions, it seems that even children in Europe have acquired the same level of ability as Moken children . However, it is said that all the children of Europe are red eyed after being torn by the seawater, this point is different as the Moken children repeat the diving more than 30 times without making their eyes completely red .


One of the reasons the Moken tribe was noticed in recent years is unique sight,Detecting the tsunami during the Sumatra EarthquakeIt was also one of the reasons that it was reported that 1,200 people living in the village had escaped to the hill so it was one male who was physically handicapped and delayed to run away. However, at this time, many of the residential areas of the seaside were destroyed, and the tideland and the forest, which are the source of food and building materials, were greatly damaged such as being covered with garret. Although the Thai government has offered aid to the Moken tribe and is offering work in the national park to migrate to the mainland of Thailand, Mr. Gislen said, "When they try to help them and to provide safety in contemporary culture, they We will lose the original culture, "he says about the difficulty of assistance.