As American astronauts spend longer stints in space, a troubling trend has turned up. More male astronauts are having problems seeing while on extended space flights.
It’s an issue that’s puzzling NASA researchers and it could jeopardize goals like the manned mission to Mars.
David Zawieja is the department head for Medical Physiology at the Texas A&M Health Science Center in Temple. He’s been helping NASA study the issue. Zawieja says the agency noticed the phenomenon over 10 years ago, when astronauts started going on much longer missions.
“They’ve accumulated enough data that they realized that about 40 or so percent of the astronauts experience some type of vision acuity loss associated with space flight,” he says.
Zawieja says almost all of the astronauts who have been affected have been male.
“Why that is is a question that remains unanswered at this point in time,” he says.
Astronaut Scott Kelly, who recently spent almost a full year in space, has helped NASA study the problem.
“He experienced some significant vision losses. He had had them before, from one of his previous trips, where he went from not wearing glasses to having to wear glasses for medium distance vision,” Zawieja says. For Kelly’s last trip, “it got even worse. He’s only one individual of course but he’s been studied quite intently.”
Zawieja says without gravity, there’s a translocation of fluid from the lower body into the upper body. He says it’s too soon to know if space travel could eventually lead to blindness.
Written by Jen Rice.