A new study led by Rachael D. Seidler, director of the University of Florida's Astraeus Space Institute, examined how factors such as sex, age, and body metrics relate to brain and eye changes in astronauts after space travel. The research, published in npj Microgravity, is among the first to detail sex-related physiological responses to spaceflight. Data showed that female astronauts exhibited by Clarence Oxford
Los Angeles CA (SPX) Oct 30, 2025
A new study led by Rachael D. Seidler, director of the University of Florida's Astraeus Space Institute, examined how factors such as sex, age, and body metrics relate to brain and eye changes in astronauts after space travel. The research, published in npj Microgravity, is among the first to detail sex-related physiological responses to spaceflight. Data showed that female astronauts exhibited a greater reduction in fluid around the top of the brain compared to males, but eye changes were most consistently observed in men.
Spaceflight Associated Neuro-ocular Syndrome, especially globe flattening - a compression at the back of the eyeball - was the leading ocular change. This phenomenon, which was more common in male astronauts, poses concerns for maintaining long-term vision during extended missions.
Globe flattening causes the rear surface of the eye to indent, which may impair vision and presents a serious health challenge for astronauts. Despite comprehensive analysis, researchers found no direct connection between the brain structure changes and globe flattening. This suggests the eyes and brain are affected by different mechanisms during space travel.
Seidler's team managed multidisciplinary work connecting neuroscience, physiology, and spaceflight performance, enabled by the HiPerGator high-speed computing cluster at UF. The separation in outcomes for eye and brain health indicates that mission medical protocols for lunar and Mars expeditions must monitor both systems independently.
"Our dataset was still only approximately one-quarter females, but since the overall dataset was fairly large we were able to examine sex differences," Seidler said. "By far the most prevalent sign of eye changes that we observed was globe flattening, suggesting that this should be the primary monitoring target for ocular health."
The findings are crucial for future astronaut missions, highlighting the need to tailor health assessments according to individual risk profiles and sex. The full study is available in npj Microgravity.
Research Report:Crewmember demographic factors and their association with brain and ocular changes following spaceflight
Related Links
University of Florida
Space Medicine Technology and Systems