When astronauts began spending six months and more aboard the International Space Station, they started to notice changes in their vision.
When astronauts began spending six months and more aboard the International Space Station, they started to notice changes in their vision. For example, many found that, as their mission progressed, they needed stronger reading glasses. Researchers studying this phenomenon identified swelling in the optic disc, which is where the optic nerve enters the retina, and flattening of the eye shape. These symptoms became known as Space-Associated Neuro-Ocular Syndrome (SANS).
Microgravity causes a person’s blood and cerebrospinal fluid to shift toward the head and studies have suggested that these fluid shifts may be an underlying cause of SANS. A current investigation, Thigh Cuff, examines whether tight leg cuffs change the way fluid moves around inside the body, especially around the eyes and in the heart and blood vessels. If so, the cuffs could serve as a countermeasure against the problems associated with fluid shifts, including SANS. A simple and easy-to-use tool to counter the headward shift of body fluids could help protect astronauts on future missions to the Moon and Mars. The cuffs also could treat conditions on Earth that cause fluid to build up in the head or upper body, such as long-term bed rest and certain diseases.
Read more at National Aeronautics and Space Administration (NASA)
Image: NASA astronaut Jonny Kim, assisted by JAXA astronaut Takuya Onishi, performs an eye ultrasound on the International Space Station. (Credits: NASA)
