Researchers find out why astronauts return to Earth with visual impairment

Astronauts and astronauts, who spend a long time on orbital stations, in most cases return to Earth with fallen vision. So far, scientists have not been able to identify the cause of this phenomenon, which means that under threat - the health of people preparing to conquer outer space in the future. Probably, now the scientific community has a clue to the solution of the phenomenon.

80 percent of astronauts have visual impairment

Researchers at the University of Miami discovered the cause leading to a partial loss of vision. According to various estimates, with the deterioration of eye health, about 80 percent of space explorers return to Earth. In many of them, the drop in vision is accompanied by intracranial hypertension. However, scientists from Miami were not ready to directly link these two phenomena until they had a clue. Earlier in the scientific community there were suggestions that the liquid under conditions of weightlessness can be redistributed in the body quite differently than it does on the Earth. It seems that these assumptions have real grounds.

What causes eye pressure?

The lead author of the study, Noam Alperin, says that under gravity on Earth, gravity pulls liquid substances down the body. However, under conditions of weightlessness, fluid migration in the opposite direction (to the head) is observed. Inflow of fluid to the brain causes an increase in intracranial pressure, and its redistribution into the orbit zone provokes an increase in intraocular pressure. Most astronauts who spend many months in zero gravity return to Earth with astigmatism. Unfortunately, in most cases, this ailment has irreversible consequences. In other words, the vision of astronauts worsens for the rest of their lives.

Scientists emphasize that this phenomenon is inherent only to those who are forced to stay at the orbital stations for a long time. Dr. Alperin states that the astronauts making short-term flights did not have a deterioration in sight.

Detailed examination

Not all body fluids were in the field of view of the research group. Scientists from Miami primarily interested in cerebrospinal fluid. This substance is designed to protect the brain and spinal cord from vibrations and shocks. Redistribution of the volume of fluid to the eye sockets provokes a deterioration of vision (the contours of the objects become fuzzy and blurred). Inflow of cerebrospinal fluid to the ventricle causes intracranial pressure. It should be noted that there were no changes in the tissues of these internal organs.

Search for protective mechanisms

The results of the study were presented at the annual meeting of the Radiological Society of North America in Chicago. According to scientists, now, when the cause of the deterioration of the view of astronauts is revealed, this will help to find a way out of this situation. NASA experts are interested in finding the solution as soon as possible. For this purpose, the space agency employees plan to recreate the conditions of weightlessness on Earth and conduct additional research.