A NASA study involving 27 astronauts has uncovered an unsettling trend among long-term spacefarers, including irregularities with the shape of their eyeballs and pituitary glands, among other things. Hang on, what did you think we were talking about?
Yes, well, not those ones.
According to The Guardian, no one thought to check how their eyes were doing until astronauts started noticing a mysterious improvement in eyesight. Sadly, for others, it had actually degraded. Curiosity obviously got the best of them and, after conducting brain scans, it became clear that not all was well with our extra-terrestrial explorers:
Four of the astronauts had swelling around the optic nerve, which could affect the transmission of signals from the eye to the brain and, in the longer term, cause nerve fibres to die off. Three of the astronauts had slightly deformed pituitary glands, though this was not thought to be harmful.
How about those who found they could see better? Seems being in space causes your eyeballs to become shorter, which does wonders for the short-sighted among us. If your vision is just fine, however, the result is long-sightedness.
The doctors involved in the study aren't exactly sure what's caused these changes, only that spending a lot of time in space is a consistent element and not all astronauts were affected equally, with some only having issues with one eye. It could be gravity, or the increased production / reduced re-absorption of cerebral fluids — until more data is available and additional research conducted, we'll just have to keep an, uh, eye on the situation.