Space Exploration Bad for the Eyes? The Truth Behind Astronauts' Deformed Eyeballs
A new research has revealed that astronauts who stay for long periods in space suffer from a strange permanent eye condition: deformed eyeballs. This mysterious condition could be detrimental to future space exploration.
According to a new study presented at the annual meeting of the Radiological Society of North America (RSNA), NASA and surgeons have observed a strange pattern in astronauts who stay for long durations in space. Space surgeons notes that these astronauts suffer from visual impairment and blurry vision, which upon further testing, reveal that the structure of their eyeballs have changed. The astronauts had a flattened eyeball and inflammde head of optic nerves, according to a press release.
Tagged as (VIIP), the condition has affected around two-thirds of the astronauts who stayed for a long time on the International Space Station (ISS).
"People initially didn't know what to make of it, and by 2010 there was growing concern as it became apparent that some of the astronauts had severe structural changes that were not fully reversible upon return to earth," said Noam Alperin, lead author of the study from the University of Miami.
Initially, scientists thought that the eyeball deformation on astronauts is due to the shifting of the fluids in their bodies while in space. However, Alperin thinks otherwise.
Alperin said that the potential cause of VIIP is the cerebrospinal fluid (CSF), a fluid that's responsible in circulating nutrients, cushioning the brain and spinal cord as well as removing waste materials. The study notes that on Earth, CSF could accommodate changes in pressure, but living in microgravity is another story, BBC reports.
"On earth, the CSF system is built to accommodate these pressure changes, but in space the system is confused by the lack of the posture-related pressure changes," Alperin explained.
To test this theory, Alperin used quantitative imaging algorithms to find a connectiion between the astronauts' eyes and the amount of CSF in their systems. He discovered that astronauts who stay longer in space experienced a flatter eyeballs and more protruted nerves than those who went on space for shorter periods of time.
"The research provides, for the first time, quantitative evidence obtained from short- and long-duration astronauts pointing to the primary and direct role of the CSF in the globe deformations seen in astronauts with visual impairment syndrome," said Aperin.
"If the ocular structural deformations are not identified early, astronauts could suffer irreversible damage. As the eye globe becomes more flattened, the astronauts become hyperopic, or far-sighted," he added.