The long-term risks of living in space include bone loss, cosmic radiation and muscle weakness, so leaving gravity behind certainly has its obstacles — and yet, that doesn’t stop people from venturing out of the stratosphere. Some of these potential hurdles have already been studied extensively or are currently being investigated, but researchers have found an important but underserved area of space to study: the brain and gravity’s effect on eyesight.

The long-term risks of living in space include bone loss, cosmic radiation and muscle weakness, just to name a few, so leaving gravity behind certainly has its obstacles. Some of these potential hurdles have already been studied extensively or are currently being investigated, but researchers at MUSC Health have found an important but underserved area of space to study: the brain and gravity’s effect on eyesight.

In a recent paper in JAMA Network Open, researchers look at Spaceflight-Associated Neuro-Ocular Syndrome (SANS) and compare brain scans before and after spaceflight.

The longer astronauts stay in space, the more they’ve reported blurry vision and eyesight problems when they return to earth, according to Mark Rosenberg, M.D., a neurology resident at MUSC Health and a researcher on the paper.

«It’s gotten to the point where astronauts actually carry extra pairs of glasses when they go into space,» said Rosenberg. «They know that their vision is going to be deteriorating up there, and they’ve even started calling them Space Anticipation Glasses. And, in fact, depending on how you define it, it affects about 70% of astronauts.»

With SANS, astronauts return to earth with altered visual acuity and struggle to distinguish between shapes at a distance. The globes of their eyes flatten, parts of their retinas show injury and their optic disks swell. Some astronauts recover from these changes in a few weeks, while others can take months or even years. There are also some who never fully recover.

Story Source: Materials provided by Medical University of South Carolina. Original written by Celia Spell. Note: Content may be edited for style and length.