Becoming an astronaut requires perfect 20/20 vision, but unfortunately, the effects of space can cause astronauts to return to Earth with degraded eyesight. Now, researchers from UT Southwestern Medical Center have developed a sleeping bag that that could prevent or reduce those problems by effectively sucking fluid out of astronauts' heads.

Axar.az reports that more than half of NASA astronauts that went to the International Space Station (ISS) for more than six months have developed vision problems to varying degrees. In one case, astronaut John Philips returned from a six-month stint about the ISS in 2005 with his vision reduced from 20/20 to 20/100, as the BBC reported.

For multi-year trips to Mars, for example, this could become an issue. "It would be a disaster if astronauts had such severe impairments that they couldn't see what they're doing and it compromised the mission," lead researcher Dr Benjamin Levine told the BBC.