How Space Travel Affects Astronauts’ Eyesight
When astronauts return from the International Space Station, many have noticed an unexpected side effect of their mission – their eyesight has changed. This phenomenon, affecting about 70% of astronauts on long-duration missions, has NASA scientists working to understand why weightlessness affects how we see.
Dr. Sarah Johnson first noticed this during her six-month stay aboard the ISS. She reported that text that was crystal clear before launch became blurry. Astronauts frequently report difficulty reading, blurred distance vision, and other visual changes that can persist for years after returning to Earth.
The condition is now known as Spaceflight Associated Neuro-ocular Syndrome (SANS) and has become one of the most pressing health concerns for long-duration space missions. Unlike motion sickness or muscle weakness, which resolve quickly back on Earth, the vision changes can be permanent.
The culprit appears to be microgravity itself. In space, fluids redistribute in the body, causing facial puffiness and increased pressure inside the skull. This elevated pressure can flatten the back of the eyeball and cause swelling of the optic nerve, which has major implications for Mars missions that could last 2-3 years.
Dr. Michael Roberts, NASA’s vision research lead, states, “We need to understand whether these changes stabilize or continue worsening over time. An astronaut with severely compromised vision could jeopardize an entire Mars mission.”
NASA is developing countermeasures, including special contact lenses, medications to reduce fluid pressure, and exercise protocols that might help maintain normal circulation. They are also testing a device called the Visual Impairment Intracranial Pressure (VIIP) chamber that could simulate Earth-like pressure conditions for the eyes.
While concerning, this research benefits everyone on Earth too. Scientists are gaining new insights into how pressure affects vision, potentially helping treat conditions like glaucoma and intracranial hypertension.
Understanding how our bodies adapt to space remains crucial as we test the limits of our bodies through longer-duration space flight. The research into solutions will continue at NASA and onboard the ISS so that when we finally reach out on a human trip to Mars, we can at least see clearly what we have accomplished!
This article was originally published by Universe Today. Read the original article.
