Eye Problems From Space Affect At Least 21 NASA Astronauts

SternisheFan sends this report from Universe Today: How does microgravity affect your health? One of the chief concerns of NASA astronauts these days is changes to eyesight. Some people come back from long-duration stays in space with what appears to be permanent changes, such as requiring glasses when previously they did not. And the numbers are interesting. A few months after NASA [said] 20% of astronauts may face this problem, a new study points out that 21 U.S. astronauts that have flown on the International Space Station for long flights (which tend to be five to six months) face visual problems. These include "hyperopic shift, scotoma and choroidal folds to cotton wool spots, optic nerve sheath distension, globe flattening and edema of the optic nerve," states the University of Houston, which is collaborating with NASA on a long-term study of astronauts while they're in orbit.

Comments

space affect?

[Anonymous Coward]

like they exhibit a spacey behavior or demeanor?

yeah, i'm not interesting in going to space

[shadowrat]

bone density plummets, muscles atrophy, eyes degenerate. Are we telling this to kids that go to space camp? Being an astronaut is as bad if not worse for your health as playing in the NFL. Of course, i find the former more interesting to follow from the comfort of my armchair.

Re:yeah, i'm not interesting in going to space

[SternisheFan]

From CBCnews, Mar 13, 2012:

Astronauts have complained for decades about vision problems such as blurriness following trips into space. A recent NASA survey of 300 astronauts found correctible near and distance vision problems in 48 per cent of astronauts who had been on extended missions and 23 per cent of those who had been on brief missions. In some cases, they lasted for years after the astronauts returned to Earth.

Fluid shifting toward head causes problems

In the new study, the astronauts had spent an average of 108 days in space. Their eye abnormalities were similar to those seen in patients on Earth with idiopathic intracranial hypertension. Patients with the condition have increased pressure around their brains for no apparent reason.

Among the astronauts in the study:

33 per cent had expansion of the space filled with cerebral spinal fluid that surrounds the optic nerve, which connects the eye to the brain.

22 per cent had flattening of the rear of the eyeball.

15 per cent had bulging of the optic nerve.

11 per cent had changes in the pituitary gland and its connection to the brain.

An earlier NASA-sponsored study of seven astronauts, published last November in the journal Ophthalmology, found similar abnormalities and also noted that they were similar to those experienced by patients on Earth suffering from pressure in the head. But it noted that astronauts did not experience symptoms usually associated with that problem on Earth, such as chronic headache, double vision or ringing in the ears.

The earlier study suggested that the problems might be caused by fluid shifting toward the head during extended periods of time in microgravity. This could result in abnormal flow of spinal fluid around the optic nerve, changes in blood flow in the vessels at the back of the eye, or chronic low pressure within the eye, the researchers said.

http://www.cbc.ca/news/technol...

Not enough

[Intrepid imaginaut]

Not enough hot green alien ladies to make first contact with yet, I surmise is the root cause of this problem.

Re:What can be done about this?

[Spy Handler]

aside from artificial gravity, nothing. No amount of exercise bike pedaling will save your optic nerves from being in zero G too long.

There isn't really any good reason to put people in orbit for 6 months+. Rotate them out every couple of months. Yes we needed data on long-term microgravity effects on the human body. We have them now, zero G does bad things to your body. So don't do it for extended periods.

Fly in the ointment is the expected trip to Mars, which will take 9 months to a year. Fortunately people like Zubrin have developed advanced technologies to deal with this. It's called a rope. Attach the Mars spacecraft to a ballast via a rope (they call it tether) and spin it until you get 1/3rd G. Problem solved.

Re:What can be done about this?

[GameboyRMH]

Eugenicsy? Maybe. Too slow? Hell yes.

Obviously...

[Type44Q]

Obviously orbital habitats either need to be spun-up or contain living quarters located within centerfuges.

Re:What can be done about this?

[ShanghaiBill]

Yet, it doesn't seem like there's a whole lot to be done about it unless we find a way to generate gravity in space.

Just spin the space station. The centripetal force can substitute for gravity. This doesn't work for small space craft, because the different forces on the head and feet will cause nausea. It is also a problem for people doing outside repairs, because any untethered tools or components will fly away. But for a large space station, such as an O'Neill Cylinder, or multi-generational starship, spinning should work fine.

Re:What can be done about this?

[ArcadeMan]

Wouldn't that be "problem 33% solved?"

Re:What can be done about this?

[sillybilly]

It is easy to create artificial gravity by spinning a cylinder and walking on the inner surface, using the centrifugal force. Like your washing machine does it. However these health problems are not related to gravity. Health problems relating purely to gravity are all muscoskeletal - atrophy of muscles from nonuse, and deterioration of bones from not being needed much, lack of stress on them.
The eye problems and heart problems come about from something else - intense cosmic rays. The space station is too friggin small to provide proper shielding. A rotating cylinder space station of 300 yard radius and half a mile length would be much better. Especially if you put many floors on it, as each floor serves as a radiation shield, and you could sleep suspended in a sleeping bag in the center weightlessness zone, the most shielded part. Of course it comes down to wall thickness, and for starters, you need at least two steel cylinders with small gap/lubricant sliding on top of each other, so in case of an iron-nickel meteorite projectile piercing through both going at 30 miles per second, and through all floors then exiting the other side, the sliding motion covers up the hole pretty fast, and does not leak the whole space station to vacuum quickly, and lets you evacuate to a different air locked segment while spacewalk outside repairs like thermite welding are under way, and the segment can be fully repressurized. The thicker the wall the better protection from cosmic rays, however, you don't want to go too thick, as the atmosphere down here on earth only protects so much, and the highest background radiation places like India from all that thorium, still have healthy populations. Without cosmic rays the rate of mutations and stillborn babies probably drops, but it also stops evolution, and new forms of beautiful or better people appearing on the scene. I wonder if there is a correlation between altitude of a city and number of stillborn babies, for a standard batch of people, such as Asians from Shanghai living in Lima, Katmandu, near the Dead Sea (below sea level), etc. Comparing indigenous people does not work as they may already be adapted to high background radiation, and in fact these high altitude Tibetan and Andes people might be better suited to be astronauts, because they've been under less insulation protections from the atmosphere above them than the rest of us, in a sense they have already been living closer to outer space, outer space is more their home than ours. However people living near simply high background radiation, such as thorium in India, at low altitude, fall under the same category.

NASA needs to get it's act together

[TomRC]

We've long known what will likely avoid these sorts of problems - create a rotating environment to simulate gravity.
While the physics principle is simple, engineering a safe rotating station is probably quite challenging.
The sort of thing NASA was created to investigate...

Zero-G is bad long term, but what about 1/6-G?

[deathcloset]

This is an unintuitive wild speculation, but I wonder if these effects are a linear function of the gravity or if there is a more complex interaction.
In other words, if Alice spent 6 monts in zero-G and Bob spent 6 months in 0.166-G, and assuming equal eye health, would Bob have less damage than Alice or more?

Obviously the human body emerged out of a 1-G environment, so the eye has evolved with those pressures. But just because removing those pressures completely may result in harm, that is not to say that removing those pressures partially would be harmful.

The only non-zero-G astronauts I know of were the Apollo folks - but I can't find any information (or anectdotes from them) on the difference in physiological effects of zero-g versus 1/6th-G.

It seems like they would have experienced less intercranial pressure and would have had an actual reference for up and down.

Oh space be a harsh mistress.

Re:Zero-G is bad long term, but what about 1/6-G?

[bthecohen]

You hit the nail on the head: this is perhaps the most fundamental unanswered question in life support for space exploration. We simply have no idea.

Originally, the ISS was slated to have a module called the Centrifuge Accommodations Module. It was intended to help answer this question. It contained a large centrifuge that could hold 2-foot-tall animal cages and simulate anywhere from zero to 2g. It would have been one of the most essential experiments on the station, because there is really no way to collect data on varying levels of microgravity on living organisms other than putting a centrifuge in zero g. Unfortunately, the (mostly assembled) module was cancelled in 2005.

The engineering implications for interplanetary missions are profound, in that it might be vastly more expensive to build a 1g artificial gravity centrifuge than, as you said, a 1/6g one. But we currently have absolutely no way of knowing how many Gs we need. It's a very tough problem.

Oh he's not a doctor

[Overzeetop]

Oh he's not a doctor. But he did stay at a Holiday Inn Express last night.

I see what you did there...

[Overzeetop]

Obviously orbital habitats either need to be...

Re:What can be done about this?

[wierd_w]

This is why the obvious solution is to compartmentalize the artificial gravity habitats:

You have a single, exterior shell, which does NOT rotate. This allows spacewalks without all those nasty issues.

Inside this shell, you have several cylendrical habitats that counter-rotate. The combined rotational force is a net zero, which is why the exterior shell does not rotate.

(Simplest configuration-- One long cylendar, with two cylendars inside. One of these rotates clockwise, the other counter clockwise. The long axis of all cylendars is conserved.)

This would allow you to use the gravitational habitats as reaction control wheels. They could also be spun down for easy maintenance-- Being INSIDE the vehicle's outer shell, the whole interstitial space between the habitat and the outer hull could be pressurized. Maintenance to the moving parts would be radically less difficult, and lost tools would only happen on exterior hull maintenance. Again, exterior hull DOES NOT SPIN.

The reason we dont design space vessels this way is very blunt: It costs a WHOLE FUCKING LOT OF MONEY to orbit just a few pounds of weight. Proper design is easy--- Logistics of lofting something that works, even halfassed, is NOT.

This argument isnt about long term space missions.

This argument is really about why we arent using the moon for staging our orbiting vehicle construction.

If we used the moon this way, we could AFFORD to build CORRECT space vehicles that DO supply sufficient shielding.

We dont, because that means having a real, self-sustaining colony on the moon, which means having joe sixpack in space, and all the trappings that go with it. (Space pubs/bars, and space hookers. No society in the history of mankind has been without them. The moon would be no different.) This is VERY unattractive to high-minded politicians and researchers. NOBODY wants to be the guy who puts space whores on the moon.

However, private industry has no such qualms. They will happily put "Candy" on the moon, to do her low G poledance routine, as long as she can pay the ficket price for her flight.

We will get there eventually; but really, we should have been more aggressive about getting things set up and running on the moon.

Politically, government has to contend with things like "Making sure single mothers and orphans get subsidized health and food services"-- Again, private industry has no such requirement.

It wont be pretty, but at least it will eventually get there. Just dont expect star trek.

Instead, the grim spectre is "The company store". (I wouldnt be surprised if the early privatized space agencies actually negotiate a fee for candy's services, and actually ship her up themselves!) The companies that fund and build the colony sites up there are going to have literal material monopolies on everything from power, to water, to air, to food. And in a potentially unregulatable environment. Nasty business.

But again-- we WILL eventually get there, but the end result wont be roses and sunshine. Government is not capable of the sustained attention focus in the face of voter interests--- and private industry has no real humanitarian interests.

Private indsutry will go anywhere and do anything that people are willing to pay money for, and will tailor its actions to maximize its financial bottom line. -- That's a two edged sword of truth. (If there's a market, and profit to be made in sacrificing babies to Satan, they would cheerfully sacrifice as many babies as possible to get that money given half the chance. Private industry is NOT a moral actor.)

There is a vast and untapped market in space. The need for orbiting telecom, and improved service and uptime of same, is only getting greater by the minute. The first group to succeed in getting a viable colony on the moon to provide manufacturing, orbiting, and service agreements for terrestrial satellites (based from the moon, where such service can be cheap) will have a veritable monopoly, PLANET WIDE. The fin