Long-term space missions may alter astronauts' vision and DNA
The latest research by the Canadian team at NASA indicates that long-term space missions can significantly change astronauts' bodies. Recent findings have demonstrated that staying in orbit significantly affects vision and eye anatomy.
According to the portal Interesting Engineering, studies suggest that long-term space missions can negatively impact astronauts' vision. Data from 13 astronauts who spent about five to six months on the International Space Station (ISS) were analysed.
concerning changes in astronauts' eyes
According to research published in the Journal of Engineering in Medicine and Biology, at least 70% of astronauts on the ISS experience Spaceflight-Associated Neuro-Ocular Syndrome (SANS). These changes include a 33% decrease in eye stiffness, an 11% decrease in intraocular pressure, and a 25% decrease in ocular pulse amplitude.
The changes manifest as a reduction in eye size, a change in focal field, and, in some cases, swelling of the optic nerve and retinal folds. Researchers suggest that the lack of gravity alters blood distribution in the body, leading to increased blood flow to the head and slowed venous circulation in the eye.
Although these changes do not pose a significant problem for six to twelve months, space agencies are cautious about more extended missions. Doubts and concerns about astronauts' health arise in the context of longer space missions, such as a trip to Mars. The effects of prolonged exposure to microgravity on eye health remain unclear.
Changes in astronauts' DNA
Staying in Earth's orbit impacts the entire body. A well-known example is astronaut Scott Kelly, who spent a year in space. An unusual side effect of the mission was a change in DNA.
Kelly has a twin brother, which allowed the space agency to study the astronaut's DNA and analyse the side effects of spending an extended time in microgravity conditions. The astronaut spent more than 500 days away from our planet, mostly aboard the International Space Station. During this mission, his telomeres, the end sections of chromosomes, significantly lengthened, despite the fact that they usually shrink with age.
Surprisingly, after returning to Earth, it took just two days for most telomeres to return to their standard length. Although most of Scott's genes returned to normal shortly after his return, about 7% showed lasting differences compared to his brother Mark's. These changes remained unchanged for two years.
Scientists are continually studying the impact of microgravity on the human body. Changes in the mechanical properties of the eye may help predict the development of Spaceflight Associated Neuro-ocular Syndrome. Currently, no preventive or treatment measures are available for these side effects.
