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Sunday, May 25, 2003Ordinarily, human eyesight becomes blurry under water because the eye is structured to see through air. But the Moken nomads, who tie stones to their waists so they submerge long enough to forage for seafood, can constrict their pupils to pin-prick size and spot pearls measuring only 1.5mm in diameter. They also squint in order to squeeze the lenses of their eyes, which temporarily thickens them and improves focus under water. "They use the optics of the eye to the limits of what is humanly possible," said Anna Gislen, a Swedish biologist who led the study. At best, the sharpest-eyed children could distinguish objects that measured 3mm across. Young snorkellers volunteered to toss aside their masks and be tested at the tourist islands of Ko Samui, Ko Phi Phi and Ko Poda. None of them could constrict their pupils at will, as the Moken did routinely on every dive. The Swedes speculated that the Moken sea gypsies must learn these skills, although after generations of scavenging the sea floor, "the ability to see well underwater could have become a genetic trait." To those who see best go the spoils. posted by Sydney on 5/25/2003 07:36:00 PM 0 comments 0 Comments: |
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