The eyesight of astronauts who stayed in space for a certain period of time is observed to lose their perfect vision. However, scientists may have finally figured out the visual impairment causes which can open avenues to developing counteract measures to protect space travelers’ vision.
Our bodies are built the way they are to accommodate the living conditions of Earth. But in the wake of delving more into space travel, we should know its effects and repercussions to our body – especially for the astronauts who are manning in the space missions.
The last decade showed astronauts losing their 20/20 vision particularly those in long-duration flights. It was a mysterious syndrome that was untreatable and irreversible even when the astronauts have come back to Earth.
What Happens to Astronauts
When NASA saw the pattern of astronauts getting blurry visions, they began further testing to get to the source of the condition. They were able to find out that the back of the astronauts’ eyeballs flattened and the back of the head of their optic nerves was inflamed. The malady is then called the visual impairment intracranial pressure (VIIP) syndrome.
The visual impairment causes, according to the initial findings of scientists, include the change in the flow of vascular fluid as it streams towards the upper body of the astronaut due to space’s microgravity. But a recent study, led by the radiology and biomedical engineering professor Noam Alperin, Ph.D., from the University of Miami Miller School of Medicine, introduced another potential culprit of the syndrome.
The cerebrospinal fluid (CSF) is a clear, colorless bloody fluid that buffers the brain and spine for mechanical and immunological protection. They are responsible for the changes of pressure in our body as we shift positions; for instance, from lying down to standing or sitting. But in space, the CSF system is “confused by the lack of the posture-related pressure changes” according to Dr. Alperin.
The Reason Behind It
Further studies were conducted to understand the role of CSF on the eye changes and spaceflight-induced visual ailments. For the first time, they were able to obtain quantitative evidence for the primary role of CSF in the condition.
The results showed the higher the CSF volume is, the more changes there are in the structure of the visual system. Longer flights also see an increased flattening of eyeballs and optic nerve protrusion.
The study is yet to be peer-reviewed but it is already considered a significant leap in learning more about the ocular changes happening in humans’ body while in space. If the visual impairment causes are not identified immediately, Dr. Alperin says astronauts could “suffer irreversible damage.”