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Scientists think they may have located the cause of the vision problems experienced by nearly two-thirds of all astronauts after long missions in weightlessness.
Prof Alperin has been looking at another potential source of the problems – the cerebrospinal fluid (CSF). This helps cushion the brain and spinal cord, and can accommodate the changes when a person moves from a lying to a standing position. “In space the system is confused by the lack of the posture-related pressure changes,” Prof Alperin explained.
The team performed high-resolution MRI scans before and shortly after spaceflights for seven long-duration astronauts. They compared the results with nine astronauts who flew into orbit for short stints on the space shuttle. The results showed that long-duration astronauts had significantly greater post-flight increases in the volume of CSF within the bony cavity of the skull that holds the eye, and also in the volume of CSF in the cavities of the brain where the fluid is produced.
The sample size is small, and the study has not yet been peer reviewed, so these results must still be taken with some skepticism.