Sunita Williams in Space Day-52: NASA Astronaut May Be at Risk of Potential Vision Problems

Washington DC: NASA astronaut Sunita Williams, currently part of the Boeing Crew Flight Test mission, has been stationed on the International Space Station (ISS) for over 50 days. During this time, she has undergone comprehensive eye examinations, along with her crew members, to study the effects of long-duration spaceflight on vision.

These examinations, monitored closely by medical professionals on Earth, included detailed scans of the cornea, lens, and optic nerve. The goal is to understand and mitigate vision issues that may arise during extended space missions. This research is crucial for developing strategies to protect astronauts' eye health.

Dr. Vineet Sehgal, Senior Consultant at Sharp Sight Eye Hospitals, highlighted the importance of these tests. “Microgravity conditions in space significantly affect the human body, including the eyes. Regular eye checkups are essential to identify and manage any problems promptly, ensuring astronauts' health and their ability to perform mission-critical tasks effectively,” he explained.

‘In Space, Fluids Move Upwards Toward Head’

Astronauts on long missions often face eye health issues due to microgravity, the most common being Spaceflight-Associated Neuro-ocular Syndrome (SANS). Symptoms of SANS include changes in vision, optic disc edema, globe flattening, and choroidal folds. These issues are primarily caused by fluid shifts in the body due to the lack of gravity. On Earth, gravity pulls fluids toward the lower body, but in space, fluids move upwards toward the head, increasing intracranial pressure and affecting eye shape and function.

Possible Health Risks for Sunita

As per media reports, the astronauts are at significant health risks due to her extended stay. The reports suggest, Williams is already facing several significant health challenges because of prolonged exposure to microgravity, which causes rapid bone density loss. This happens because, in microgravity, bones do not bear the weight, leading to a loss of density similar to osteoporosis.

Though astronauts are trained in rigorous exercise regimes designed to counteract these effects, "bone loss remains to be an inevitable consequence of prolonged space missions."

The extended stay exacerbates these issues, increasing possible risks of fractures, the report added. Other than this, microgravity presents several other challenges such as fluid redistribution, which causes face puffiness and a decrease in fluid volumes in the legs. It also leads to complicating blood pressure upon returning to Earth.

The microgravity also impacts one's urinary system, by increasing the risk of kidney stones due to elevated calcium levels in urine. Furthermore, hormonal changes and shifts in gut microbiota also complicate nutrient absorption and overall health. This includes radiation sickness and increased risk of cancer.

What Delayed Sunita's Return

The two NASA astronauts were on a seven-day mission to test the Starliner and certify it for human flights. However, issues came up with the spacecraft, forcing them to remain aboard the flying laboratory for over a month now. They got stuck in space after their Starliner spacecraft experienced trouble in the propulsion system. 

Understanding and addressing these eye health challenges are vital for the safety and well-being of astronauts. As space missions become longer and more frequent, maintaining astronauts' eye health is critical. Ongoing research and regular eye checkups are essential to develop effective countermeasures and treatments to protect astronauts' vision and overall health during their time in space.