Why do astronauts become myopic after flying_ Some astronauts return to Earth from long-term space missions with incurab

Why do astronauts become myopic after flying? Some astronauts return to Earth from long-term space missions with incurable myopia. Now scientists have found the cause, but finding a solution to this problem is easier said than done. Researchers at the University of Miami's Miller School of Medicine say the problem is related to changes in the volume of fluid in the cerebrospinal shaft around the brain and spine.

Prolonged exposure to microgravity can lead to a buildup of cerebrospinal fluid, which flattens astronauts' eyes, which is why they are nearsighted. The buildup of cerebrospinal fluid can also cause astronauts' optic nerves to protrude, which is also not good, because the optic nerve, which is responsible for sending signals from the brain to the retina.

This has led to myopia in astronauts who work on long-term space missions, and there is no clear solution to this problem. There's plenty of evidence that astronauts who have completed a long-term space mission have blurred vision when they return to Earth.

Noam Alperin, the study's lead author, said in a statement: "At first, people didn't know what was going on, but in 2010 the problem became even more urgent because some astronauts didn't recover their anatomy after returning to Earth. This condition is known as visual impairment intracranial pressure (VIIP) and occurs in about two-thirds of astronauts on long-term missions to the International Space Station.

Prior to the new study, scientists thought the problem was related to the changes in fluid in the blood vessels of astronauts' upper bodies during exposure to microgravity. New research, which will be presented at the annual meeting of the Radiological Society of North America, suggests that the normally protective cerebromedullary fluid may be the culprit. On Earth, the cerebrofluid system is able to adapt to sudden changes in stress, such as when people lie down and then sit up or stand up.

But in space, this system can become very confusing due to the lack of posture-related pressure changes. Brain scans taken by the astronauts before and after their long-term mission showed that their eyes flattened and the optic nerve protrusion increased after returning to Earth.

Importantly, astronauts experienced a large increase in the volume of cerebrospinal fluid (CSF) in the cavity produced by the optic nerve and cerebrospinal fluid (CSF) after the flight. With this new information, scientists will have to look for new ways to prevent and treat them. At the same time, space will remain unsuitable for human settlement.