Vision problems from weightlessness

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This article provides an excellent review of the vision problems caused by long term exposure to weightlessness, including the efforts to study the problem on Earth.

Bottom line:

Before a human trip to Mars — a journey of six-to-nine months that NASA says it wants to achieve by the 2030s — researchers agree that VIIP [the name given to this problem] must be understood much better. VIIP could be the first sign of greater dangers to the human body from microgravity. “We’re seeing the visual and neural, ophthalmic manifestations of it,” Barratt said. “I’m fairly certain this is a bit more global than that.”

Richard Williams, the chief health and medical officer at NASA, agrees that what we do not know about VIIP still poses the biggest threat. Ironically, one of the only ways to get more knowledge is spend more time in microgravity. “The longer we stay in space, the more we’re going to learn,” Williams said.


  • ken anthony

    Researchers agree that before a human trip to Mars…

    Who the hell are these researchers to decide what risks the actual colonists are willing to take to get to mars?

    At least they acknowledge that learn by doing works.

  • Localfluff

    It says it hurts 80% of astronauts. So send the other 20% to Mars. Problem solved, move on.

  • Alex

    Localfluff: Restly 20% may be affected later one. It seems a prinicipal problem if 80% are hurt. Why we shall send men to Mars in a deadly environment? There is no urgent need. Robots are able do the job.

  • Localfluff

    Alex: Mars is not for everyone. Not in a generation anyway. Instead of canceling all spaceflight, one could simply recruit astronauts who are naturally resistant to the side effects of gravity. I’ve heard many times that the eye problem only hits a fraction of the men and never any woman. I think most of those 80% never noticed anything and that it was just possible to clinically measure a potential change in their eyes. A few have lasting (modest) problems, but maybe they would’ve anyway, at what age our eyesight deteriorates varies alot individually.

    The article is a lobbying piece for giving more money to this particular research group. It is not at all alarming, it is actually very good news for long term human space flight! Simply select the Mars crew from those who have spent 6-9 months on the ISS without any problem. It costs nothing and delays nothing. The first few crews should better spend that time in LEO anyway before they go as a training, and also as a health diagnostics for how they react to microgravity. (Preferably in a space station more similar to the actual Mars transfer ship).

    About 540 humans have been to space. Only 3.3% died there (in Earth atmosphere, not by microgravity or radiation or even a malfunction in orbit). The dangers are being managed very well. But the hypochondria in the space community is hysteric anyway, every detail is manically blown up to a show stopper. Failed researchers try to get money by lobbying scare propaganda on the politicians and bureaucrats. Many professions in the world are more dangerous.

    I think that this waste of billions on very low risk of modest inconvenience for the astronauts is the biggest reason for why people in general think that everything space related is a ridiculous waste of tax money, which makes politicians refuse even mentioning space.

  • Localfluff

    The ISS has cost about as much as all cancer research in the world! To deal with irrelevant problems like this, everyone’s eyesight deteriorates, and Earth is not exactly plagued by microgravity. I understand that people in general are angry at the human space programs and want to get rid of them, they are such an extremely enormous waste of tax money for nothing as it is mismanaged today. Everyone loves the robotic probes, though. If humans are to compete in space, then we need to recruit the right stuff and leave the primadonna attitude back home. It is as if it’s managed by nerds who never played ball because of the risks involved with running on grass.

  • Localfluff

    Microgravity is not worse than 1G. There are bad things and good things, it’s just different. What research has been done on the health benefits of microgravity? None of course, the whole space medicine fraud is biased to make up lame excuses for why human spaceflight should be stopped, until trillions of tax money has been given away to lazy corrupt failed pseudo “researchers”.

  • Alex

    Hey, Localfluff, good comments.

  • wayne

    If ‘m not entirely mistaken, there is also a problem with high-energy particles striking astronaut’s eyes— produces intermittent flashes as they collide with the rods/cones.

    We have millions of years on evolutionary-biology, within a gravity field, and we are not going to overcome those problems just by wishing them away.

  • Localfluff

    We invented glasses.

  • BSJ

    Glasses don’t fix excess pressure in the skull! It appears to be much more than just a loss of visual accuity…

  • pzatchok

    Its time to build a spinning station.

    Actually do construction in space.

  • wayne

    –good point.
    Personally, I Like “Space,” and Mars is very interesting & intriguing.
    I also believe humans belong in Space. But I have no delusions that there are not serious issues with a long-term presence in space & we are just scratching the surface as to what those problems are & potential solutions (or adaptations, biological or contrived.)

    I’ll say it again– humans have millions of years of evolutionary-biology, specifically in a gravity field. Our DNA is literally fine-tuned for gravity. (Or I should say more precisely, gravity is responsible for shaping, via selection, our DNA.)

    I have no doubt, however, that our distant future will be in space & future generations will undoubtedly adapt, by definition, or they will not succeed.

    (To be clear– human’s won’t “adapt” simply because we “want-to,” only those specific-mutations that enable a greater chance of survival and reproduction in low/zero-gravity environments will be passed on. And to be clear further– evolutionary & environmental pressures only work at the Population level and not on individual members of a species.)

    –As well, (our saving grace, possibly) our large brains allow us to invent stuff to by-pass, as it were, some but not all evolutionary selection pressures. (We can transmit our current knowledge to future generations, above & beyond pure biological adaptation.)
    I am also convinced those future generations, in space, will develop into a distinct branch of our modern Homo Sapiens Sapiens.
    Just as we are now the only surviving branch of our more distant homo-sapien relatives. (We are alive today, only because they could hack it back then. Our progeny will survive, precisely because we could hack it, now.)

    As a related tangent– Nassim Taleb has done considerable writing on the concept of “fragility.” Although not specifically on space-travel per se, the concepts, I believe, are vital to a future in space.
    His contention is; the opposite of “fragility” is not “robustness,” it’s “anti-fragility.”

    Humans function best (physically & psychologically) under a certain minimal “push-back” from the environment & other people. It’s a symbiotic self-sustaining relationship.

    “Nassim Taleb Talks Antifragile, Libertarianism, and Capitalism’s Genius for Failure”
    (I challenge anyone to watch just 5 minutes and tell me they aren’t intrigued by what Taleb says.)

    We as yet, do not fully understand “biology/evolution” within a gravity field, much less in minimal or zero-gravity. We are discovering things every day & that knowledge will be essential going forward.

    If I am not mistaken, people who have spent considerable time in space, aren’t physically capable of functioning properly, initially upon their return to gravity fields. I don’t know what the gravity on Mars is off hand, but there will be no one at the landing-site to help.

    I fully support robotic, un-manned exploration of Mars (and elsewhere) & if SpaceX wants to do supply runs to Mars– that’s great. (it’s fantastic! it really is!)
    My preference however, would be to establish a Colony on the Moon and then work toward making it self-sustaining.

    Our skeletons, circulatory system, organs, etc., are all shaped by being in a gravity field. We have yet to fully (functionally) determine which of these systems are potential Bugs or Features, in differing environment’s.
    Asking the correct (functional) questions will be as vital as determining the correct (functional) solutions.

    –I will absolutely agree with you however, that some things are more driven by pet-projects and theories, from certain interest groups/scientists, rather than pure scientific pursuit.
    It’s always been that way. (Humans do, what they always have done, it’s our “nature.”)

    As always, are goal should be to minimize the chaff & focus on the wheat, as much as is practicable.

    (I absolutely enjoy your commentary LocalFluff, even if I differ with it at times. You are certainly one of the more colorful commenters on BtB!)

  • wayne

    pzatchok :

    On board with your thought, 100%!

  • Localfluff

    I’m sorry for hyperboles, but it makes easier to drive home the main point, and is a bit more fun to type. I think microgravity health issues is a red herring that diverts too much attention from things that are relevant to HSF.

    wayne: The best way to find out is to try it. ISS crews should stay a Mars conjunction period of 26 months, that would cut crew launch costs by 77% as a bonus too. The launches and landings are much much more dangerous than the staying in microgravity. Multi year stays would dramatically improve the safety of the astronauts. 26 months is needed for Mars’ moons, which I think will be visited before Mars’ surface. After that 6-9 months in microgravity is enough for human interplanetary spaceflight this century, since Mars’ .38g certainly will feel like home. If zero gee hell brakes loose before 26 months, then just skip the moons until we can land on Mars after making a short stop at them on the way.

    No negative health effects of any substance have ever been observed from microgravity during up to a year’s stay. If it hadn’t been proven so many times, I would’ve been among those who were afraid that Gagarin could’ve died from a few minutes in microgravity. That it takes a few days to get mentally used to gravity again kinda shows how well humans adapt to zero G. You feel dizzy if you spin around quickly too, it is not a health problem, just a very temporary inconvenience.

    There are many health problems caused by gravity, and many kinds of accidents. There are individual variations in health, for example, some people get seasick too easy to become sailors. Many astronauts obviously have no change at all in their eyes, pick them. Some special interests do not like simple solutions to the “problems” which motivates their existence. They work hard to not solve them.

    Spinning a spacecraft so slightly that it would not need a tether or special design might go a long way to improve the environment. Dust and loose objects would tend towards the floor instead of being in everyone’s face, astronauts could sit and lie down without belts, intuitive orientation might improve. And still they would have the benefit of moving around light as if they were feathers and use the full volume of indoor space. It might be enough to give biological orientation too while at sleep which could reduce the pressure in the upper body, which I agree doesn’t sound like a health benefit, although it evidently has never endangered anyone of the ~540 who’s been up there between a day and a year.

  • We really, really need a variable gravity lab in LEO. Currently we have no idea how much gravity humans need to stay healthy.

  • wayne

    Mike Borgelt succinctly nailed it:
    “Currently we have no idea how much gravity humans need to stay healthy.”

  • wayne

    “If there is something in nature you don’t understand, odds are it makes sense in a deeper way that is beyond your understanding. So there is a logic to natural things that is much superior to our own.
    Just as there is a dichotomy in law: ‘innocent until proven guilty’ as opposed to ‘guilty until proven innocent’, let me express my rule as follows:
    -What Mother Nature does is rigorous until proven otherwise; what humans and science do is flawed until proven otherwise.”
    ― Nassim Nicholas Taleb,
    “Antifragile: Things That Gain from Disorder”

  • PeterF

    OK guys lets step back a bit and try to apply some logic here. You’re all wrapped around the axle because researchers found, statistically, microgravity MAY have a long term deleterious effect on vision. Lets not ignore the fact that many astronauts are well past their “nightclubbing” days. A time when people can honestly say that they didn’t hear the wife tell you to take out the trash or the grass needs cutting, or that they refuse to admit they were squinting when reading the paper (that might get you booted out of the program).

    So what do we know? We know that high gravity stresses can damage eyesight. Ask any fighter pilot. (Its one of the reasons they don’t give rides in the centrifuge anymore) :( .

    All of the people who have been exposed to microgravity have also been exposed to high-G to get there.

    I’d be willing to wear coke bottles for a chance to explore Mars.

  • Edward

    Localfluff wrote: “26 months is needed for Mars’ moons, which I think will be visited before Mars’ surface.”

    I am hearing that a “consensus” of those studying Mars missions think that a manned Mars orbital mission should be first — possibly as early as 2028. I suspect, however, that SpaceX is not part of that consensus and will aim for the surface first, at about the same time.

    An orbit-first mission may focus on Phobos for study.

    I agree with DougSpace, that a tethered and spun-up capsule-booster combination could provide enough artificial gravity, inexpensively, to prevent some of the micro-gravity problems that we have been seeing. However, we do not have a lot of tether experience, in space, and that may need some more investigation and work before committing to it.

  • wayne

    I was trying to dig a bit deeper on physical issues & Space, and ran across these folks:

    Space Safety Magazine
    >numerous topics of interest for both the layman & professional.

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