John Charles, NASA/Johnson Space Center (IMAGE) NASA/Johnson Space Center Caption John Charles, Ph.D., associate manager for International Science, NASA Human Research Program, explains the relevance of conducting visual impairment investigations during NASA’s One-Year Mission. Credit Brett Redden/NASA Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.