Superior underwater vision in a human population of sea gypsies
Superior underwater vision in a human population of sea gypsies
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DOI：
10.1016/s0960-9822(03)00290-2
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发表时间：
2003-05-13
期刊：
影响因子：
9.2
通讯作者：
Warrant, EJ
中科院分区：
文献类型：
--
作者：
Gislén, A;Dacke, M;Warrant, EJ
人类不太适应水下视觉。在空气中，弯曲的角膜表面占眼睛屈光力的三分之二，当空气被水取代时，这一点就会消失[1]。尽管如此，东南亚的一些海上吉普赛人部落以海洋为生，孩子们在没有视觉辅助的情况下从海底收集食物[2]。这是一个了不起的壮举，当一个人考虑到人眼不集中在水下和小物体应该仍然无法解决。我们测量了海洋吉普赛人（Moken）儿童的视力，发现孩子们在水下的视力比人们想象的要好得多。他们的水下视力（6.06周/度）是欧洲儿童（2.95周/度）的两倍多。我们的研究表明，Moken儿童通过最大限度地收缩瞳孔（1.96 mm，而欧洲儿童为2.50 mm）并适应已知的人类性能极限（15-16 D）来实现其上级水下视觉[3]。这种极端的反应在莫肯儿童中是常见的，但在欧洲儿童中却完全没有。由于他们完全依赖海洋，莫肯人很可能从这一战略中获得巨大利益。
Humans are poorly adapted for underwater vision. In air, the curved corneal surface accounts for two-thirds of the eye's refractive power, and this is lost when air is replaced by water [1]. Despite this, some tribes of sea gypsies in Southeast Asia live off the sea, and the children collect food from the sea floor without the use of visual aids [2]. This is a remarkable feat when one considers that the human eye is not focused underwater and small objects should remain unresolved. We have measured the visual acuity of children in a sea gypsy population, the Moken, and found that the children see much better underwater than one might expect. Their underwater acuity (6.06 cycles/degree) is more than twice as good as that of European children (2.95 cycles/degree). Our investigations show that the Moken children achieve their superior underwater vision by maximally constricting the pupil (1.96 mm compared to 2.50 mm in European children) and by accommodating to the known limit of human performance (15-16 D) [3]. This extreme reaction-which is routine in Moken children-is completely absent in European children. Because they are completely dependent on the sea, the Moken are very likely to derive great benefit from this strategy.