Jan 12, 2022 05:35 PM
https://www.universetoday.com/153959/now...your-eyes/
EXCERPTS: 70% of astronauts who spend time on the International Space Station (ISS) experience swelling at the back of their eyes, causing blurriness and impaired eyesight both in space and when they return to Earth. [...] In an effort to understand the cause of these eye problems, researchers at the Medical University of South Carolina used MRI scans of twelve ISS astronauts to measure the intracranial venous system (veins that circulate blood to the brain) before and after flight...
[...] The effect of spaceflight on the eyes is known as spaceflight-associated neuro-ocular syndrome (SANS). SANS is so common, according to Dr. Mark Rosenberg, one of the study’s authors, that “it’s gotten to the point where astronauts actually carry extra pairs of glasses when they go into space. They know that their vision is going to be deteriorating up there, and they’ve even started calling them space anticipation glasses.”
The physical changes in the eyes include flattening of the globes, injury to the retinas, and the swelling of nerves in the eyes. For some astronauts, the eyes recover within weeks of returning to Earth, but the healing process can sometimes take much longer.
The root cause of SANS, according to the paper Rosenberg and his colleagues produced, seems to be correlated with veins swelling behind the eyes. Weightlessness causes the distribution of blood in the body to change, with fluid moving towards the head and eyes more than is usual on Earth, where gravity reduces the flow to these areas...
[...] There is still, of course, more to learn. For one thing, the team hopes to do more research on how SANS risks might differ between men and women... (MORE - missing details)
EXCERPTS: 70% of astronauts who spend time on the International Space Station (ISS) experience swelling at the back of their eyes, causing blurriness and impaired eyesight both in space and when they return to Earth. [...] In an effort to understand the cause of these eye problems, researchers at the Medical University of South Carolina used MRI scans of twelve ISS astronauts to measure the intracranial venous system (veins that circulate blood to the brain) before and after flight...
[...] The effect of spaceflight on the eyes is known as spaceflight-associated neuro-ocular syndrome (SANS). SANS is so common, according to Dr. Mark Rosenberg, one of the study’s authors, that “it’s gotten to the point where astronauts actually carry extra pairs of glasses when they go into space. They know that their vision is going to be deteriorating up there, and they’ve even started calling them space anticipation glasses.”
The physical changes in the eyes include flattening of the globes, injury to the retinas, and the swelling of nerves in the eyes. For some astronauts, the eyes recover within weeks of returning to Earth, but the healing process can sometimes take much longer.
The root cause of SANS, according to the paper Rosenberg and his colleagues produced, seems to be correlated with veins swelling behind the eyes. Weightlessness causes the distribution of blood in the body to change, with fluid moving towards the head and eyes more than is usual on Earth, where gravity reduces the flow to these areas...
[...] There is still, of course, more to learn. For one thing, the team hopes to do more research on how SANS risks might differ between men and women... (MORE - missing details)