Now a new worry has been added to the concerns about the bodily changes astronauts undergo in a weightless environment: blurred vision.
“Periodically, we do different tests,” Mike Fossum, commander of Expedition 29 to the International Space Station (ISS), told CBS News. “The first is visual acuity test and ultrasound (test) on their eyes to measure details of the eyeball.”
A recent report by the US National Academy of Sciences said that seven of the 15 former crew members who were tested experienced blurred vision due to intracranial pressure and swelling of the optical disk. There is some concern there may be lingering affects on the astronauts’ vision.
Keeping watch on the astronauts’ eyesight aboard the ISS is Satoshi Furukawa, a qualified astronaut and medical doctor with more than 10 years of clinical experience. He blasted off from the Cosmodrome in Russia for the ISS early in June.
On arriving at the ISS he tweeted to 36,000 followers on his feed that his head felt heavy. He then explained in a later tweet, “This is considered a brain’s adaptation to weightlessness. Your head feels heavy due to fluid shift.” He has tweeted more than 400 times from space.
“I would like to share these experiences with everyone from the perspective of a doctor,” Furukawa said. “I hope to report back first-hand about the differences in the way my body feels in space and on the ground.”
However, the main concern is the problem of blurred vision and whether it might cause lingering permanent damage, somewhat in the same way as glaucoma can affect vision. Some 35 percent of all ISS astronauts tested have reported greater or lesser problems with blurry vision.
So far the current crew has not had any problems, reported Furukawa. “We periodically inspect each other and no problems at all.”
Furukawa also is tasked to carry out a number of experiments during his time on the ISS. When Japan’s space agency, JAXA, announced they were sending a doctor into space, they asked the public for suggestions on space-medicine experiments to see how the human body reacted to a weightless environment. Ten were selected.
“I’m looking forward to performing these experiments in space,” Furukawa said.