Space flight associated neuro ocular syndrome (SANS), was discussed by Professor David Brown, NASA’s Head Ophthalmologist. Earth’s gravity causes most of our blood volume to be contained within the lower limbs. In space, because of a lack of gravity, there is a redistribution of bodily fluids within the head and orbit.
The redistribution of fluid causes long sightedness in astronauts such that they are launched into orbit with a series of reading spectacles !!
Interstitial fluid accumulates within the retina and choroid, causing choroidal folds.
It causes swelling of the optic disc and can lead to a misshapen globe. Astronauts often experience a change in vision upon return to earth, though thus far, there have been no serious retinal complications causing vision loss. SANS is important, for should NASA launch a manned mission to Mars, the duration of the space journey would be three years.
Avoiding retinal swelling and vision loss would be mission critical.
BJH 4.7.24. 🇬🇧 general election day 🇬🇧
