Along the coastlines and islands of the Andaman Sea lives the Moken tribe, a small, traditionally nomadic group often referred to as “sea nomads.” For generations, the Moken have lived in close relationship with the ocean, relying on it for food, travel, and cultural identity.
Among their most fascinating traits is an ability that has drawn the attention of scientists around the world: Moken children can see underwater with a clarity far superior to that of most humans, in some cases up to twice as sharp.
Who the Moken Are
The Moken inhabit parts of southern Thailand, Myanmar, and nearby islands, spending much of their lives on boats or near the shore. Traditionally, they travel in wooden vessels called kabang, moving with the seasons and tides.
Fishing, diving, and gathering shellfish form the backbone of their subsistence lifestyle, and from a very young age, Moken children are immersed in the marine environment.
This intimate connection to the sea is not just cultural, but physical. Swimming and diving are everyday activities, not specialized skills. Children often begin diving before they can read, learning to navigate underwater spaces with confidence and precision.
The Discovery of Unusual Underwater Vision
The Moken’s exceptional underwater vision came to broader scientific attention in the early 2000s, when researchers began testing how well Moken children could see beneath the surface.
In controlled experiments, they were asked to identify shapes and patterns underwater.The results were striking: Moken children consistently outperformed European children by a wide margin, seeing details that others could not.
What made this discovery even more intriguing was that the Moken children were not using masks or goggles. They were seeing clearly with the naked eye, in an environment where human vision normally struggles due to light refraction and blurring.
How Regular Vison Usually Fails Underwater
Human eyes evolved primarily for seeing in air. Underwater, the difference in how light bends between water and the cornea is reduced, which normally results in blurred vision.
Most people experience a dramatic drop in visual sharpness when they open their eyes underwater, making it difficult to focus on fine details.
For the Moken, this limitation appears to be reduced. Tests showed that their pupils constrict more strongly underwater, increasing depth of field and improving focus. At the same time, their eyes seem better able to accommodate, or adjust focus, to the watery environment.
Evolution, Adaption, or Learned Skill?
A key question raised by these findings is whether the Moken’s underwater vision is genetic or learned. Scientists believe the answer lies somewhere in between.
The human eye has more flexibility than is typically used, and Moken children appear to train their visual system from a very young age through constant exposure to underwater tasks.
Interestingly, studies showed that when non-Moken children were trained to dive regularly, their underwater vision improved as well, though not always to the same degree.
This suggests that the Moken ability is not a separate biological mutation, but an exceptional use of human visual potential shaped by culture, environment, and early practice.
Why It Matters for Survival
For the Moken, sharp underwater vision is not a novelty, but a survival tool. It allows them to spot shellfish, sea cucumbers, and small fish on the ocean floor, often in low-light conditions.
Being able to distinguish edible species from dangerous ones can mean the difference between a successful meal and serious injury.
This skill also contributes to the Moken’s reputation as expert divers, capable of holding their breath for extended periods and navigating complex underwater terrain with ease.
Cultural Knowledge and the Sea
The Moken’s relationship with the ocean extends beyond physical abilities. Their oral traditions, navigation skills, and ecological knowledge reflect generations of close observation.
Famously, during the 2004 Indian Ocean tsunami, many Moken recognized the warning signs of an approaching wave and moved to higher ground, saving countless lives.
Their underwater vision is just one part of a broader system of knowledge and adaptation that has allowed them to thrive in a challenging environment.
Modern Pressures and a Changing Future
Today, the Moken way of life is under threat. Coastal development, fishing restrictions, and pressure to settle permanently on land are changing how younger generations live.
As children spend less time in the water, the conditions that foster exceptional underwater vision may be disappearing.
Scientists and anthropologists see the Moken as a powerful example of how human abilities can be shaped by environment and culture. Their story challenges assumptions about biological limits and highlights the remarkable adaptability of the human body.
The Moken do not possess superhuman eyes, but their lives show how extraordinary human perception can become when shaped by generations of living with the sea.
