Space Blindness
Someday in the future, a fearless crew may conquer all the odds and reach the end of a dangerous eight-month trip to Mars. But as they pull into orbit around the planet, they realize their pilot — and no one on the team — can properly see the controls anymore.
Space blindness, for lack of a better term, is a steady degradation of vision that many astronauts have reported. The effect seems to become worse the longer someone has spent in space: Around 30 percent of those on short-duration missions have reported some blurring of eyesight while the number is double for astronauts on long-term missions. The effect has only recently come to light since previous generations of astronauts were scared to report the effect for fear of being grounded.
Researchers as yet don’t know the cause of these symptoms but some have suggested they are related to increased fluid pressure in the head pushing the optic nerve into the back of the eyeball. This condition, known as papilledema, can result in permanent vision loss. Blindness is certainly the worst-case scenario, though even blurred vision could badly affect an astronaut and make them unfit for duty, especially on long interplanetary voyages.
