Finding solutions:
Wearing goggles in space can help prevent vision problems among astronauts, advise NASA experts
(Natural News) The weightless environment of outer space can degrade the eyesight of an astronaut, especially during long-duration missions. But a new study suggests that wearing protective goggles of any type will help preserve the person’s sight in micro-gravity and zero-gravity conditions.
NASA researchers noticed that astronauts who stayed aboard the International Space Station (ISS) for extended periods often developed issues with their eyes. Impaired vision and other eye-related health problems might haunt them for years.
The solution proved simple: Wear goggles. The protective eye-wear applies slight pressure around the eyes, which may counteract the pressure drop inside the eyeball in weightless environments.
The researchers identified swimming goggles and safety glasses as good candidates to protect the eyes and health of astronauts.
Wearing the same goggles as athletes and construction workers may help prevent the condition called “space flight-associated neuro-ocular syndrome” (SANS). SANS develops when the pressure of the fluids within the eyes diminishes due to the absence of gravity in space.
The NASA study showed better vision in astronauts who wore safety glasses developed for use in construction, sports, and other physically risky activities. The goggles increased the intraocular pressure of the fluid inside the eyes, counteracting the negative effect of weightlessness.
SANS appears in one out of every three ISS astronauts. It has become a serious health concern among NASA health experts.
Patients with SANS report seeing white spots on their retinas called “cotton wool spots.” They also experience swelling in their optic nerve.
“These findings suggest modestly increasing intraocular pressure with swimming goggles could be used to mitigate spaceflight-associated neuro-ocular syndrome,” explained Universities Space Research Association (USRA) researcher Dr. Jessica Scott. “Elucidating the mechanistic underpinnings of SANS is important to protect the health of astronauts and continued human space exploration.”
Medical scans of astronauts with SANS showed that the pressure inside their brains changed during space missions. Researchers theorized that weightlessness contributed to the appearance of spinal fluid responsible for the pressure changes.
The USRA research team held their experiment at NASA’s Johnson Space Center. They gave swimming goggles to 10 of their participants. The rest of the group went without any protective eye-wear.
Scott reported that participants who wore swimming goggles experienced a modest increase in intraocular pressure. The boost may help astronauts avoid the worst effects of SANS during extended trips in space, such as the planned missions to the moon or Mars.
“Confirmatory studies are required to determine the appropriate duration and intensity of artificial increase in IOP in space flight to modulate SANS,” she said. “In addition, evaluation of the safety of prolonged or daily goggle use is needed.”
Numerous health problems arise from spending prolonged periods in zero gravity environments. Most commonly, astronauts lose mass in their bones and muscles, which undermine their physical capabilities.
Astronauts may perform poorly during critical tasks and get injured more easily and frequently. Their cardiovascular system and aerobic capacity may also diminish. And the longer the space mission, the worse these issues get.
Fortunately, astronauts will recover from many of the harmful effects caused by long space missions once they return to Earth. But researchers only caught the threat to eye health in recent years, and they are looking for ways to alleviate the risks of impaired vision so far away from home.
The findings of the USRA researchers may benefit NASA’s plans to return to the moon in 2024, as well as a mission to Mars in 2033.
Wearing goggles in space can help prevent vision problems among astronauts, advise NASA experts – NaturalNews.com
The weightless environment of outer space can degrade the eyesight of an astronaut, especially during long-duration missions. But a new study suggests that wearing protective goggles of any type will help preserve the person’s sight in micro-gravity and zero-gravity conditions. NASA researchers...www.naturalnews.com
See:
Valeri Polyakov - Wikipedia
More:Beings Not Made for Space
Scott J. Kelly, right, in 2011 with the Russian astronauts Oleg Skripochka, left, and Aleksandr Kaleri after six months aboard the International Space Station.Credit...Bill Ingalls/NASA
HOUSTON — In space, heads swell.
A typical human being is about 60 percent water, and in the free fall of space, the body’s fluids float upward, into the chest and the head. Legs atrophy, faces puff, and pressure inside the skull rises.
“Your head actually feels bloated,” said Mark E. Kelly, a retired NASA astronaut who flew on four space shuttle missions. “It kind of feels like you would feel if you hung upside down for a couple of minutes.”
The human body did not evolve to live in space. And how that alien environment changes the body is not a simple problem, nor is it easily solved.
Some problems, like the brittling of bone, may have been overcome already. Others have been identified — for example, astronauts have trouble eating and sleeping enough — and NASA is working to understand and solve them.
Then there are the health problems that still elude doctors more than 50 years after the first spaceflight. In a finding just five years ago, the eyeballs of at least some astronauts became somewhat squashed.
The biggest hurdle remains radiation. Without the protective cocoon of Earth’s magnetic field and atmosphere, astronauts receive substantially higher doses of radiation, heightening the chances that they will die of cancer. How much of a cancer risk later in life is acceptable?
At the Johnson Space Center here, the home base for NASA’s human spaceflight program, scientists probably have until the 2030s to dissect these problems before the agency sends astronauts to Mars — a mission that would take about 2.5 years, or nearly six times the current standard tour of duty on the space station.
The longest any human has been off Earth is almost 438 days, by Dr. Valery Polyakov on the Russian space station Mir in 1994 and 1995. (Two private organizations, Inspiration Mars and Mars One, have announced plans to launch a manned interplanetary flight sooner and have had no problem attracting people despite the risks, known and unknown.)
NASA recently announced that it would continue operating the space station until at least 2024, in part for additional medical research.
NASA officials often talk about the “unknown unknowns” — the unforeseen problems that catch them by surprise. The eye issue caught them by surprise, and they are happy it did not happen in the middle of a mission to Mars.
In 2009, during his six-month stay on the International Space Station, Dr. Michael R. Barratt, a NASA astronaut who is also a physician, noticed he was having some trouble seeing things close up, as did another member of the six-member crew, Dr. Robert B. Thirsk, a Canadian astronaut who is also a doctor. So the two performed eye exams on each other, confirming the vision shift toward farsightedness.
They also saw hints of swelling in their optic nerves and blemishes on their retinas. On the next cargo ship, NASA sent up a high-resolution camera so that they could take clearer images of their eyes, which confirmed the suspicions. Ultrasound images showed that their eyes had become somewhat squeezed.
NASA is now checking astronauts’ eyesight before, during and after trips to the space station.
The issue turns out not to be new. Many space shuttle astronauts had complained of changes in eyesight, but no one had studied the matter.
“It is now a recognized occupational hazard of spaceflight,” Dr. Barratt said. “We uncovered something that has been right under our noses forever.”
Dr. Barratt said the vision shift had no effect on his ability to work in space. The concern, however, is that the farsightedness may be just a symptom of more serious changes in the astronauts’ health. “What are the long-term implications?” he said. “That’s the $64 million question.”
[...]
A decade ago, NASA scientists worried that astronauts were returning to Earth with weaker bones, their density draining away by 1 to 2 percent per month. In space, the body does not need to support its weight, and it responds by dismantling bone tissue much faster than on Earth.
NASA turned to osteoporosis drugs and improved exercises, like having the astronauts run while strapped to a treadmill. The up-and-down pounding set off signals to the body to build new bone, and NASA scientists reported that astronauts then came back with almost as much bone as when they had left.
“That was huge,” said Scott M. Smith, a NASA nutritionist.
Because both the formation and destruction occur at accelerated rates, “we don’t know if that bone is as strong as when you left,” Dr. Smith said. But the scientists now feel that bone loss is not a showstopper for a long-duration mission.
For the eyesight issues, scientists have more questions than answers. They suspect that the adverse effects result largely from the fluid shift, the higher pressure of the cerebrospinal fluid in the skull pushing on the back of the eyeballs, but that has not been proved. And that theory does not explain why it usually affects the right eye more than the left, and men far more than women.
Dr. Smith has also found that the astronauts who experienced a shift in vision had increased levels of the amino acid homocysteine, often a marker for cardiovascular disease. That may suggest that a zero-gravity environment sets some biochemical process in motion.
Artificial gravity could be generated by spinning the spacecraft like a merry-go-round, alleviating both the bone loss and the fluid shift. But that would also add complexity to a mission and raise the potential for a catastrophic accident.
But the eye issue “could be something that drives us back to artificial gravity,” Dr. Barratt said.
The lack of gravity also jumbles the body’s neurovestibular system that tells people which way is up. When returning to the pull of gravity, astronauts can become dizzy, something that Mark Kelly took note of as he piloted the space shuttle to a landing. “If you tilt your head a little left or right,” he said, “it feels like you’re going end over end.”
That may not be as big an issue for a Mars spacecraft that lands autonomously, and in which the astronauts have time to rest before getting out of their seats.
Regarding radiation, NASA operates under a restriction that astronauts should not have their lifetime cancer risk raised by more than three percentage points, but that is an arbitrary limit. Mark Kelly, for one, said he would be willing to accept twice that if he had a chance to go to Mars.
There may be other complications, though. At Brookhaven National Laboratory on Long Island, scientists are bombarding mice with radiation that mimics high-energy cosmic rays that zip through outer space. Those mice take longer to navigate a maze, suggesting that the radiation may be damaging their brains.
Scientists say it may damage other organs, including the heart, nervous system and digestive system. “Those could be acute effects,” said William H. Paloski, the head of NASA’s human research program. “We just don’t know. It’s one we’re looking at.”
Beyond the body, there is also the mind. The first six months of Scott Kelly’s one-year mission are expected to be no different from his first trip to the space station.
But Dr. Gary E. Beven, a NASA psychiatrist, said he was interested in whether anything changed in the next six months. “We’re going to be looking for any significant changes in mood, in sleep, in irritability, in cognition,” he said.
[...]
In a Russian experiment in 2010 and 2011, six men agreed to be sealed up in a mock spaceship simulating a 17-month Mars mission. Four of the six developed disorders, and the crew became less active as the experiment progressed.
“I think that’s just an example of what could potentially happen during a Mars mission, but with much greater consequence,” Dr. Beven said. “Those subtle changes in group cohesion could cause major problems.”
Dr. Charles said he thought NASA could already send astronauts to Mars and bring them back alive. But given the huge expense of such a mission, he said it was crucial that the astronauts arrived productive and in great health.
“My goal,” he said, “is to see a program that doesn’t deliver an astronaut limping to Mars.”
Beings Not Made for Space (Published 2014)
Swelled heads, atrophied legs, radiation threats — space takes a toll on the human body, and some health problems still elude doctors more than 50 years after the first spaceflight.www.nytimes.com
Weightlessness and Its Effect on Astronauts
Weightlessness, or the absence of gravity, has several short-term and long-term effects on astronauts.
www.space.com