“This presents additional requirements for corrective lenses inflight for astronauts as they try to do their work,” Lindstrom said. The cause is swelling of the choroid, flattening of the globe shortening the axial length of the eye and sometimes associated disc edema. “After 8 to 12 weeks in space, some astronauts start to shift hyperopic, developing blurry vision at distance,” Lindstrom said. Lindstrom is one of a handful of ophthalmologists and industry leaders with diverse backgrounds who convened twice last fall as part of a special advisory group to the National Space Biomedical Research Institute (NSBRI) in Houston, a NASA-funded consortium. This can result in disc edema and choroidal swelling.” The core etiology is probably related to elevated venous pressure, which then causes an elevated cerebral spinal fluid pressure. But in weightlessness, not only is this assist absent, but up to 2 L of fluid shifts headward from the lower body.
“In the head, gravity assists blood return to the heart.
“When you are in space, you do not have gravity like we do on Earth,” OSN Chief Medical Editor Richard L. The hope is that in-flight monitoring and treatments will counter the detrimental effects of living in essentially a gravity-free environment. NASA is banding together with thought leaders in ophthalmology and industry to try to remedy vision problems encountered by astronauts in space for lengthy periods of time. If you continue to have this issue please contact to Healio