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Air and Water Vision of the Atlantic Flying Fish, Cypselurus heterurus

Naturevolume 214pages307309 (1967) | Download Citation



AMPHIBIOUS vision for all animals with curved corneas requires an exceptional range of focusing ability. Whereas the cornea in air focuses light like a strong positive lens, under water it becomes a very weak positive lens because it has approximately the same refractive index as water. Thus, land animals become hypermetropic (far-sighted) in water and aquatic animals become myopic (near-sighted) in air. In some fish, this gain or loss of lens power amounts to as much as 20 to 30 dioptres1.

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    Baylor, E. R., and Shaw, E., Science, 136, 157 (1962).

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    Verrier, M. L., Bull. Soc. Zool. France, 59, 535 (1934).

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    Verrier, M. L., Ann. Biol. Paris, Ser. 3, 24, 209 (1948).

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  1. Woods Hole Oceanographic Institution, Woods Hole, Massachusetts



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