If you were one of the myriad of children who grew up wanting to be the next Neil Armstrong and longed for Buzz’s swanky spacesuit when you watched Toy Story, then you were probably imagining a lifetime cruising around the stars having a bit of fun with gravity along the way. One thing that you most likely didn’t imagine though, was having blurred vision.
Sadly, it turns out that that’s one of the things which you may well be most likely to end up with. A recent study sponsored by NASA has exposed an array of changes and impairments in the sight of astronauts out in space for periods of 6 months or longer; the most common of which – blurred vision – lasting as much as years after the sufferer’s return to earth.
The study focused on seven astronauts who were all around 50 years old and who had all been involved in long periods of space travel. Research showed that a blurring of vision had occurred in all of the subjects, and is reported to have started as little as six weeks into their travel. As well as this, more in depth study highlighted a number of persistent abnormalities in the group including a flattening of the back of the eye ball, folds in the light-sensitive tissue behind the retina and excess fluid and swelling of the optic nerve.
The obvious reasoning for these changes would initially seem to be the increase in pressure inside the head when travelling through atmospheres, but none of the astronauts reported any other typically related symptoms such as headaches or ringing in the ears. Instead, the scientists behind the study are lead to believe that the causes may be an abnormal flow of spinal fluid, low pressure in the eye or changes in blood flow resulting from increased fluid around the head when spending long periods of time in space.
Added to this is the typical age of an astronaut. Few of us are likely to graduate from college or university and jump straight into a spaceship, and the extensive training required means most are in at least their 40s; an age when the average person typically begins to suffer from retinal weakening anyway.
Implications and action
The results of the study have posed some crucial problems to NASA and other experts; the biggest of which being the obvious health risks of launching long-duration space travel such as the exploration of Mars.
As a consequence, a number of actions have been taken to protect astronauts’ safety, including comprehensive eye exams and testing and a series of pre and post-flight examinations to highlight any changes.