The Impact of Space Travel on Astronauts Vision

The Impact of Space Travel on Astronauts Vision

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The Impact of Space Travel on Astronauts VisionImage credits: Thomas323

Since the monumental moon landing in 1969, the whole world has been fascinated by the possibility of space exploration. From apocalyptic science fiction movies about alien invasions, to rumours of life on Mars… interest in space is prevalent in many realms of our modern culture.

While many of us may start out life dreaming of being an astronaut, as we get older and wiser we appreciate the demands of such a specialised job, and the risks that journeying to outer space may carry.

So the possibilities of long term effects from space travel don’t come as a huge surprise to most people…although they are slightly less dramatic than movies predict (returning to earth to find that man’s reign has been usurped by apes)!

The Problem

Travelling into outer space is no simple procedure. Astronauts are at a peak of physical fitness which includes 20/20 vision. However recent studies have shown that some astronauts who have spent periods of about a month or longer in space have reported vision issues when they return back to earth. They are no longer able to focus as well as before, and may need to wear glasses.

The University of Texas Health Science Centre in Houston conducted an MRI experiment to look into these vision complaints. 27 astronauts who had spent more than a month in space took part. It was found that 60% have what is called ‘intracranial hypertension’ – this is high fluid pressure in the skull.

Other symptoms were slightly more varied – 1/5th showed a flattening of the rear of the eyeball which affected their ability to focus.

It was also found that the longer they had spent in space, the more likely they were to suffer from the condition.

The Cause

Conditions are, of course, very different in outer space to on earth – the most obvious is the lack of gravity.

On earth, our hearts work to counteract gravity and pump blood around our body to reach all our vital organs and prevent it from pooling towards our feet. However their ‘weightlessness’ (due to lack of gravity) in outer space means that all bodily fluids, such as blood, naturally float upwards.

Many astronauts explain their experience of this as a feeling of ‘fullness’ in their head on long journeys. Interestingly, spicier foods are popular on space trips as they help to clear the sinuses!

What This Means for the Future

We may have only just begun to tap into the vast potential of space exploration, but this obviously poses a serious issue. 60% of astronauts that spend over one month in space reporting vision problems when they return to earth is quite a concerning figure.

Future plans of space exploration include travelling to Mars. This would certainly involve being out in space for a period much longer than one month. With there being no way of knowing who would or wouldn’t be affected, these health risks complicate the selection process of those who would take part in the epic journey.

Dr. Larry Kramer, who led the team at the University of Texas, says “at this point we’re just raising the issue…but once you’re headed to Mars, there’s no turning back”.

Featured images:
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Steph McLean blogs regularly about eye health related issues. She has contributed this article on behalf of Lenstore, an online contact lens store that also offers in-house Optical Advice to customers.

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