See Like a Dolphin

Have you ever opened your eyes while diving in the ocean without a mask and realized that you really can't see very well? Well, children among a nomadic sea faring people known as the Moken can see underwater with total clarity - but what's really interesting is other children can learn it in a matter of weeks.

The Moken people have historically been totally dependent upon the ocean surrounding the Mergui Archipelago, islands off the southwestern coast of Myanmar. For nine months of the year, they live on boats, so Moken children spend a lot of time in the water and help gather seafood.

For two decades, a Swedish scientist, Anna Gislen, studied these children to learn how they see clearly underwater. When she measured the clarity of their vision against a group of European children, the Moken had more than twice the visual acuity. She thought they were constricting their pupils, like a camera lens, in order to increase their depth of field. That's the distance between the nearest and farthest objects in focus. Measurements proved they constricted their pupils to the maximum known limit for a human. Gislen also found they were either consciously or unconsciously changing the shape of their lenses to improve focus.

What's fascinating is European children could be taught this ability. After eleven training sessions over one month, they developed the same visual acuity. Seals and dolphins have similar abilities.

Sadly, the traditional Moken culture is disappearing. A 2004 tsunami that destroyed much of the Moken homeland has pushed them inland and forced other employment. Though these sea nomads may disappear they've taught us how adaptable the human body can be.