In space, squashed eyeballs are a real and present danger.
The disorder, known as spaceflight-associated neuro-ocular syndrome (SANS), can adversely affect an astronaut’s vision during a lengthy mission such as a six-month stay aboard the International Space Station (ISS). More than half of returning crewmembers exhibit signs of the condition to some degree.
It’s an issue that needs to be overcome if astronauts are ever to go on multiyear missions to the moon, Mars, and possibly beyond.
The good news is that the University of Texas is on the case, with scientists offering a solution in the form of a high-tech sleeping bag.
Eyeball pressure
SANS occurs when fluid gathers in the head, with the pressure causing progressive flattening of the eyeball, swelling of the optic nerve, and vision impairment.
On Earth, fluid gathers in our head when we lie down to sleep, but during waking hours, gravity pulls that fluid back into our bodies when we stand, easing any pressure inside our head. But microgravity conditions aboard the ISS mean that there’s always a certain amount of fluid in the head, as there’s no gravity to pull it down.
The eye disorder, which for most astronauts clears up once they return to Earth, prompted a team at the University of Texas in Dallas to develop a high-tech sleeping bag (below) that could prove vital for long-duration space missions.
A solution
Designed in collaboration with outdoor retail firm REI, the team incorporated a suction device into a solid-frame sleeping bag that attaches to the user’s waist. As the person sleeps, the device works to draw fluid from his or her head, thereby relieving any potentially damaging pressure on the eyeballs.
“We don’t know how bad the effects might be on a longer flight, like a two-year Mars operation,” said team leader Benjamin Levine, professor of internal medicine at the University of Texas Southwestern Medical Center. “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.”
Additional concerns
Levine adds that extended stays in space may also increase the chances of developing an irregular heartbeat, and even impaired cognitive abilities — concerns that require more scientific research.
“It’s certainly possible there are other effects of brain pressure we haven’t documented yet,” Levine said.
He said that a number of astronauts report something known as the “space stupids,” where they “make more mistakes than they think they should. Whether that has anything to do with the inability to lower the pressure, we don’t know.”
Levine said his team’s research will hopefully pave the way for safer missions to faraway places.
Commenting on his team’s current work, he said: “This is perhaps one of the most mission-critical medical issues that has been discovered in the last decade for the space program. I’m thankful for the volunteers who are helping us understand, and hopefully, fix the problem.”
