Long Space Missions May Harm Astronauts’ Eyes
Extended space travel can cause eye and brain abnormalities in astronauts, researchers have found. For the study, published online in the journal Radiology, investigators used MRI scans to examine the eyes and brains of 27 astronauts who spent an average of 108 days in space aboard the space shuttle and/or the International Space Station. Eight of the 27 astronauts underwent a second MRI exam after a second space mission that lasted an average of 39 days.
The study authors found that among those who experienced a lifetime total of more than 30 days of exposure to microgravity, 33 percent of the astronauts had expansion of the cerebral spinal fluid space surrounding the optic nerve, 22 percent had flattening of the rear of the eyeball, 15 percent had bulging of the optic nerve, and 11 percent had changes in the pituitary gland and its connection to the brain.