Space Travel and Vision Loss United States researchers are teaming up with the Polaris spaceflight program to better understand why astronauts experience vision changes - and even significant vision loss - when they return to Earth. More than 70% of astronauts experience a phenomenon known as Spaceflight Associated Neuro-Ocular Syndrome or SANS. Researchers at Augusta University said the changes in vision "start happening on day one". "We suspect it has to do with a shift in cerebrospinal fluid in the optic nerve sheath. On Earth, gravity pushes that fluid down and it drains out, but in space it floats up and presses against the optic nerve and retina," the University's Dr Matt Lyon said. Using portable handheld ultrasound Dr Lyon's team hope to figure out the mechanism and predict who is most likely to experience SANS. Next steps could include working to develop and fine tune countermeasures that would decrease fluid volumes in the head during spaceflight. Tony Ireland Evolve Optometry Shop G03, Village Centre, Batemans Bay | 4472 8080 www.evolveoptometry.com.au evolve OPTOMETRY AW7405433 Space Travel and Vision Loss United States researchers are teaming up with the Polaris spaceflight program to better understand why astronauts experience vision changes - and even significant vision loss - when they return to Earth . More than 70 % of astronauts experience a phenomenon known as Spaceflight Associated Neuro - Ocular Syndrome or SANS . Researchers at Augusta University said the changes in vision " start happening on day one " . " We suspect it has to do with a shift in cerebrospinal fluid in the optic nerve sheath . On Earth , gravity pushes that fluid down and it drains out , but in space it floats up and presses against the optic nerve and retina , " the University's Dr Matt Lyon said . Using portable handheld ultrasound Dr Lyon's team hope to figure out the mechanism and predict who is most likely to experience SANS . Next steps could include working to develop and fine tune countermeasures that would decrease fluid volumes in the head during spaceflight . Tony Ireland Evolve Optometry Shop G03 , Village Centre , Batemans Bay | 4472 8080 www.evolveoptometry.com.au evolve OPTOMETRY AW7405433