Scientists are hopeful that a new vacuum device can simulate the experience of earth-bound gravity for astronauts in outer space. If this device proves successful, many of the eye problems astronauts develop in outer space missions may become a thing of the past.
Since there's no gravity in outer space, a great deal of pressure is applied to astronauts' eyes each and every day. No matter if they're sitting, standing, or floating around, simply being in outer space is equivalent to spending an entire day on earth laying flat on the ground. As you could imagine, this can have deleterious effects on an astronaut's vision.
In a microgravity or zero-gravity environment, the human body's cerebrospinal fluid, located around the brain and spinal cord, doesn't work like it normally does on earth. This fluid is usually regulated by intracranial pressure (ICP) as we stand, sit, and lie down. Without any gravity to work with in space, however, this cerebrospinal fluid just floats around and contributes to the flattening out of the eyeballs. This leads to serious problems, such as optic nerve protrusions and eye inflammation. The official eye condition astronauts develop is called vision impairment intracrainial pressure (VIIP).
Researchers at the University of Texas Southwestern Medical Center published an interesting paper recently that found ICP is higher in people who experience zero-gravity than in people who sit or stand for long periods of time on earth. They did find, however, that ICP is slightly lower for people in zero-gravity than for those who lay down all day.
One researcher on this study, Dr. Justin Lawley, told reporters that when gravity is removed from the environment, "the pressure in your brain goes up and it pushes on the back of your eye." As this pressure continually flattens out the back of an astronaut's eyes, visual problems almost always manifest.
There is hope, however, to prevent these visual impairments altogether. The Texan research team went on to test a negative pressure box on a few participants as they went into zero-gravity. The pressure box was situated right on a person's stomach and was attached to a vacuum. Researchers found that with the vacuum turned on for 20-minute intervals, each of the participants' experienced less pressure inside their eyeballs.
Everyone involved in this study is hopeful that this invention could help simulate earth-bound gravity in outer space. This would take a great deal of pressure off of the astronauts' eyes, and it would also help balance the astronauts' circadian rhythms.
Scientists are still studying the long-term effects of using this device. They are mainly interested in how this device can lower a person's ICP and pull excess blood away from a person's skull.
A few other research facilities have teamed up with the professors in UT Southwestern Medical Center to make even more health products for space travelers. One such device is intended to help simulate sleeping in an upright position. Some other companies are working on negative pressure sleeping bags for astronauts.
Although it's hard to tell what product will be approved next, the future for eye health in outer space looks bright.