Tag Archives: vision problems

Cause of vision problems in space pinpointed?

New research suggests that scientists have pinpointed the cause of the vision problems astronauts experience from long term weightlessness.

The new research showed that intracranial pressure in zero-gravity conditions, such as exists in space, is higher than when people are standing or sitting on Earth, but lower than when people are sleeping on Earth. The researcher’s finding suggests that the constancy of pressure on the back of the eye causes the vision problems astronauts experience over time.

More important, the research has also suggested a possible cure.

“The information from these studies is already leading to novel partnerships with companies to develop tools to simulate the upright posture in space while astronauts sleep, thereby normalizing the circadian variability in intracranial pressure, and hopefully eliminating the remodeling behind the eye,” said Dr. Levine, who holds the Distinguished Professorship in Exercise Sciences.

The researchers have continued studying whether it is possible to lower intracranial pressure by means of a vacuum device that pulls blood away from the head. They previously showed that a negative pressure box that snuggly fits the lower body can lower intracranial pressure when applied for 20-minute periods. They will soon be testing the effect of the lower body negative pressure device on eye remodeling when negative pressure is applied for eight-hour periods. “Astronauts are basically supine the entire time they are in space. The idea is that the astronauts would wear negative pressure clothing or a negative pressure device while they sleep, creating lower intracranial pressure for part of each 24 hours,” said first author Dr. Justin Lawley, Instructor in Internal Medicine at UT Southwestern and a researcher at the IEEM.

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Astronauts on ISS this week initiated a four year study of the vision problems that scientists have discovered occur to some individuals after long exposure to weightlessness.

Astronauts on ISS this week initiated a four year study of the vision problems that scientists have discovered occur to some individuals after long exposure to weightlessness.

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Research on ISS has found that prolonged spaceflight causes vision problems and might even damage the human eye.

Research on ISS has found that prolonged spaceflight causes vision problems and might even damage the human eye.

There had been hints of this discovery in an earlier report, but today’s paper is the first published science on the subject.

The results are not only important for finding out the medical challenges of weightlessness. They illustrate once again the need to do long extended flights on ISS. Without that research we are never going to be able to fly humans to other planets.

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A new study has been released detailing the vision problems experienced by astronauts on space flights longer than six months

A new study has been released detailing the vision problems experienced by astronauts on space flights longer than six months. Hat tip to Clark Lindsey.

The visual system changes discovered by the researchers may represent a set of adaptations to microgravity. The degree and type of response appear to vary among astronauts. Researchers hope to discover whether some astronauts are less affected by microgravity and therefore better-suited for extended space flight, such as a three-year round trip to Mars.

In their report, Drs. Mader and Lee also noted a recent NASA survey of 300 astronauts that found that correctible problems with both near and distance vision were reported by about 23 percent of astronauts on brief missions and by 48 percent of those on extended missions. The survey confirmed that for some astronauts, these vision changes continue for months or years after return to Earth.

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Blurred vision a risk for astronauts who spend months in space

Blurred vision is now considered a serious risk for astronauts who spend months in space.

According to one NASA survey of about 300 astronauts, nearly 30 percent of those who have flown on space shuttle missions – which usually lasted two weeks — and 60 percent who’ve completed six-month shifts aboard the station reported a gradual blurring of eyesight.

This story is a followup on information contained in an earlier National Academies report on astronaut staffing.

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