I have lately become interested in a medical phenomenon of which I am sure you are aware: Spaceflight‑Associated Neuro‑Ocular Syndrome (SANS).
It appears to arise from a set of interrelated disturbances in cranial and orbital fluid mechanics, venous hemodynamics, and tissue biomechanics produced by prolonged exposure to microgravity. No single unifying mechanism has been proven; current clinical and translational evidence supports a multifactorial model in which cephalad fluid shifts trigger downstream alterations in cerebrospinal fluid (CSF) dynamics, translaminar pressure relationships, ocular interstitial fluid balance, and vascular structure/function. Individual anatomic and physiologic susceptibility factors modulate whether and how these primary perturbations produce optic nerve head edema, globe flattening, choroidal changes, and visual dysfunction.
Thank you for the reply ... Yes, we've known for years that long-term exposure to microgravity can cause eye damage. I haven't kept up on it, but I remember one article which suggested it had something to do with the width of a certain nerve. The phenomenon tends to happen to men but not women. The nerve was thinner in women.
NASA and the Russians have experimented with pressure suits to force body fluids up into the cranium to see if that helps.
This is just one of the many problems humanity has to resolve if we're going to be serious about prolonged life in microgravity. That, or create artificial gravity by spinning the spacecraft.
I have lately become interested in a medical phenomenon of which I am sure you are aware: Spaceflight‑Associated Neuro‑Ocular Syndrome (SANS).
It appears to arise from a set of interrelated disturbances in cranial and orbital fluid mechanics, venous hemodynamics, and tissue biomechanics produced by prolonged exposure to microgravity. No single unifying mechanism has been proven; current clinical and translational evidence supports a multifactorial model in which cephalad fluid shifts trigger downstream alterations in cerebrospinal fluid (CSF) dynamics, translaminar pressure relationships, ocular interstitial fluid balance, and vascular structure/function. Individual anatomic and physiologic susceptibility factors modulate whether and how these primary perturbations produce optic nerve head edema, globe flattening, choroidal changes, and visual dysfunction.
Thank you for the reply ... Yes, we've known for years that long-term exposure to microgravity can cause eye damage. I haven't kept up on it, but I remember one article which suggested it had something to do with the width of a certain nerve. The phenomenon tends to happen to men but not women. The nerve was thinner in women.
NASA and the Russians have experimented with pressure suits to force body fluids up into the cranium to see if that helps.
This is just one of the many problems humanity has to resolve if we're going to be serious about prolonged life in microgravity. That, or create artificial gravity by spinning the spacecraft.