On February 20, 1962, John Glenn, became the first American to orbit the Earth. And fifty years later, astronauts still face the unknowns of space. There is new evidence that prolonged weightlessness, or even short periods without the pull of gravity, can have lasting physical impacts on the human body. In December of last year, in a paper published by the American Academy of Opthamology, an Anchorage doctor looked at how space travel can effect eyes.
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