NASA has ambitious plans to send humans to Mars within the next 15 years. However, a significant challenge remains unresolved—an unknown condition affecting astronauts’ eyesight. This condition, called spaceflight-associated neuro-ocular syndrome (SANS), alters vision by causing optic nerve swelling, retinal wrinkles, and changes in the eye’s shape. Despite over a decade of research, scientists are yet to pinpoint its exact cause, risk factors, or preventive measures. According to international news updates, this syndrome poses a considerable risk to long-term space travel.
The Growing Concern Over SANS Among Space Experts
Dr. Tyson Brunstetter, an aerospace optometrist at the Johnson Space Center, recalls first learning about the condition in 2011. Initially, he believed NASA would resolve it quickly. However, more than a decade later, he is now part of the team investigating SANS. NASA classifies it as one of its ‘red risks’ for a Mars mission, alongside radiation exposure and psychological stress. Since prolonged exposure to microgravity increases the likelihood of developing SANS, experts worry about its impact on astronauts’ performance during a nine-month journey to Mars.
How Space Affects Astronauts’ Vision
Studies reveal that some astronauts experience vision changes as early as ten days into spaceflight. While many astronauts have reported changes in visual acuity, only about 20% of cases qualify as severe SANS. The condition is primarily marked by optic-disc swelling and retinal thickening, which may not be immediately noticeable to the affected individual. Though most symptoms resolve after returning to Earth, some structural changes, such as eyeball flattening, may persist. Technology news today highlights that NASA provides astronauts with specially designed glasses to adjust for these vision shifts while in space.
The Mystery Behind SANS: Fluid Shift and Other Possible Causes
The leading theory attributes SANS to the fluid shift that occurs in microgravity. On Earth, gravity ensures that bodily fluids, including blood and cerebrospinal fluid, are evenly distributed. However, in space, these fluids accumulate in the head, potentially leading to increased pressure on the eyes. Scientists originally believed that elevated intracranial pressure was the sole culprit, but newer studies suggest multiple contributing factors, including metabolic shifts and genetic predisposition.
Could Carbon Dioxide and Vitamin Deficiencies Play a Role?
Another hypothesis involves carbon dioxide levels, which are significantly higher in the International Space Station (ISS) than on Earth. High CO2 levels may increase blood flow to the brain, thereby worsening pressure-related eye issues. Additionally, researchers have found a link between SANS and elevated homocysteine levels, a condition often associated with vitamin B12 and folic acid deficiencies. Genetic studies further indicate that astronauts with specific gene variants might require higher vitamin intake to counteract SANS. These findings have led to ongoing studies in which astronauts receive vitamin supplements to assess their potential benefits.
Possible Solutions: Mechanical Countermeasures and Artificial Gravity
To mitigate SANS, researchers are exploring countermeasures such as the chibis suit—a vacuum device designed to pull fluids back toward the lower body. Other solutions include venoconstrictive thigh cuffs, which slow down blood movement out of the legs without restricting arterial flow. Despite these efforts, further testing is needed to determine their effectiveness.
A more comprehensive solution may involve artificial gravity. In theory, a spacecraft with a built-in centrifuge could simulate Earth’s gravity and restore normal fluid distribution. This idea, commonly seen in science fiction, remains challenging to implement due to weight and engineering constraints. However, smaller alternatives, such as astronaut-powered bicycle centrifuges, are being considered as potential solutions.
The Future of Space Medicine: Finding a Cure for SANS
Despite these ongoing challenges, scientists remain committed to solving the mystery of SANS. International news updates frequently cover new research and technological advancements aimed at tackling this issue. With NASA actively testing various solutions, including vitamins, mechanical interventions, and genetic studies, experts believe that a breakthrough may eventually make long-duration space missions safer. As technology news today continues to report on advancements in space medicine, the race to protect astronauts’ vision remains a priority for the future of interplanetary travel.
