Could extended space missions make astronauts go blind?

[Image, REUTERS: Soyuz TMA-21 carrying International Space Station (ISS) crew members U.S. astronaut Ron Garan and Russian cosmonauts Andrey Borisenko and Alexander Samokutyaev, descends, 92 miles (148 km) southeast of the city of Zhezkazgan, September 16, 2011. The Russian Soyuz space capsule with three astronauts on board landed safely in Kazakhstan last Friday, leaving a single three-man crew aboard the International Space Station.]

The LA Times reports that 60% of astronauts who have completed 6 months aboard the International Space Station reported blurring of eyesight upon return.

A newly discovered eye condition found to erode the vision of some astronauts who have spent months aboard the International Space Station has doctors worried that future explorers could go blind by the end of long missions, such as a multiyear trip to Mars.

Although blindness is the worst-case scenario, the threat of blurred vision is enough that NASA has asked scores of researchers to study the issue and has put special eyeglasses on the space station to help those affected.

"We are certainly treating this with a great deal of respect," said Dr. Richard Williams, NASA's chief health and medical officer. "This [eye condition] is comparable to the other risks like bone demineralization [loss] and radiation that we have to consider…. It does have the potential for causing mission impact."

(via @bwjones)