Pacific Islanders Can Focus Their Pupils To See Clearly Underwater

The Moken are a nomadic, Southeast Asian people that number between 1,000 and 3,000, (persecution has followed them and whittled their numbers through the millenia) with a unique language and culture.  They live in small boats which function as their kitchens, bedrooms and main form of transport; only during monsoons, will they build huts and live on the land.  They forage for fish, mollusks, and sandworms (for food) with nets and spears and barter the shells, sea snails, and oysters they find with the Chinese or Malay that they come into contact with.

They are oft referred to by the outside world as "sea gypsies," and are known to scatter at the sight of outsiders.

The most unique thing about these people, though, is that they have adapted to override their body's pupil dilation in low light.  It gives them immense clarity of sight underwater and the children develop it at a very early age.

Watch, as an infrared camera picks up the amazing biomechanic in action

http://en.wikipedia.org/wiki/Moken_people

http://ngm.nationalgeographic.com/2005/04/sea-gypsies/ivanoff-text