Here's Why

Sea Gypsies See Undersea

The Sea Gypsy Moken people who live among the islands of Thailand and Myanmar can see twice as clearly underwater as anybody else, but without needing goggles. They have normal vision above the water. Anna Gislén, of Sweden's Lund University studied the nomadic hunter-gatherers who dive for tiny shellfish and other food from the ocean floor at depths of down to twenty-three metres underwater. The children are able to pick out small brown clams from amongst small brown stones that the Swedish scientists were unable to see even with goggles. Underwater, the human eye normally needs an extra layer of air from goggles to see anything more than a blur. This is because the light bends more travelling from air into the eye than from water into the eye. The Moken people have learned to control the muscles around their lenses so that they can voluntarily bend their lenses beyond what untrained people can do. More remarkably they have conscious control of the size of their pupils, and they contract their pupils to a tiny dot to better focus the light underwater. Its just like getting a better picture from a camera by using a smaller aperature, or hole for the light. Back in Sweden, they were able to teach school-children the tricks of shrinking their pupils and bending their lenses more, with about six months of training. The researchers fail to mention that the other time your eyes' pupil size changes, is when you are more interested in someone - its a social signal. The dilated pupils of someone who is interested, is more attractive. Learning the Moken skill of being able to consciously control your pupils to dilate when you want, could give you an edge not only underwater, but in flirting.

About the author: Ian Woolf lives in Sydney, has a degree in Applied Science, worked as a solar astronomer, software engineer, systems programmer, webmaster, research assistant, Cisco CCNA tutor, Physics laboratory demonstrator, Computational Theory lecturer, and subject coordinator; while changing his career to freelance writing and broadcasting. Listen to Ian on the Diffusion radio science show on radio 2SER 107.3FM Monday at 6:30pm in Sydney or streaming audio on www.2ser.com, or listen to the Diffusion podcasts. You should follow me on twitter, here

Posted by iwoolf at July 22, 2005 7:29 PM