I told you to stop going into space, if you keep doing it you'll go blind!
Hey, pupils!
Julian here for DNews.
Scientists have long been stumped as to why some astronauts who spend an extended period
of time in space end up with vision impairment.
Well, NASA could be one step closer to solving this nebulous mystery thanks to research from
the University of Miami, which concluded that astronauts who spent approximately six months
or more in space had a higher volume of cerebrospinal fluid than those who had shorter trips.
Now, let's just be clear, cerebrospinal fluid is a very good thing.
It helps protect the brain and spinal cord, delivers nutrients to nervous system tissue,
and removes waste products from the brain.
However, too much of a good thing, is an awesome thing.
But too much of an awesome thing is bad.
The researchers found that cerebrospinal fluid, which normally adjusts to pressure changes
on earth, gets discombobulated by the microgravity in space and begins to build up near the eye
socket and in certain cavities of the brain.
This added pressure of cerebrospinal fluid could flatten out the back of the Astronaut's
eyeballs, changing the shape of the retina, inflaming the optic nerve, and causing choroidal
folds which are essentially wrinkles on the inside of their eyeballs.
The condition is known as visual impairment intracranial pressure syndrome.
"Visual impairment" is putting it mildly.
In 2005, astronaut John Phillips spent six months at the International Space Station,
during which time his vision went from 20/20 to 20/100.
That means he had to stand 20 feet away from a line of letters to see them clearly, while
the average person can make them out at 100 feet.
A similar impairment happened to astronaut Robert Thirsk in 2009 after also spending
six months at the station.
Though both astronauts saw gradual improvements after returning home, their vision was never
fully restored to its original state.
Astronaut Scott Kelly also fell victim to the space-induced vision loss, and today is
forced to rely on reading glasses since returning from his year in space in 2015.
It's difficult to test if fluid-buildup is the culprit because the only way to measure
the increased pressure accurately would be to drill a hole in the astronaut's skull
or do a spinal tap in space.
Talk about turning it up to 11.
It also doesn't explain why only around 20% of Astronauts who went on long missions
come down seeing worse than when they went up.
So other causes have been proposed, like a vitamin or folate deficiency.
Most strangly is the idea that the vision loss is caused by polycystic ovarian syndrome
(or PCOS) which, as you might expect, causes cysts on ovaries.
Seems a little odd, considering all the astronauts who have suffered vision loss were men and
I'm going to wager they don't have ovaries.
And even if they did, their ovaries aren't in their eyeballs.
Again, I'm assuming.
But the name is misleading, even for women: 20% of women who have it don't have polycystic
ovaries.
They do have a hormone imbalance though, which is the underlying cause of the cysts.
And male relatives of women with PCOS sometimes have similar symptoms, so it may also affect
men.
Researchers at the Johnson Space Center noticed that like the women with PCOS, the visually
stunted spacefarers had higher levels of one-carbon metabolites like the amino acid homocysteine
in their blood.
When they looked closer, they found the astronauts have even more in common with women with PCOS,
like the same genetic traits and thicker retinal nerve fiber layers.
As a result some NASA scientists believe further research on PCOS could help explain why some
male astronauts return with vision damage.
Whether scientists are researching fluids of the brain or the non-existent ovaries of
men, this has become an issue NASA takes seriously.
And for good reason.
With America's plans to send humans to Mars by the 2030s, scientists have a lot to figure
out to ensure astronauts don't go blind on their way to the Red Planet.
You eyeballs might not survive space even in a space suit.
But would they bug out Total Recall style if the suit broke?
Trace talks about how your unprotected body would handle a spacewalk here.
So you have a ticket to Mars but there's a 20% chance you'll go blind.
Do you take it?
Let us know in the comments, subscribe for more and I'll see you next time on DNews.
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