On October 29, 1998, astronaut John Glenn made history for the second time becoming the oldest man to fly in space aboard the space shuttle Discovery. Credit: NASA

Early detection of glaucoma saved the sight and the remarkable career of late US senator and pioneering astronaut John Glenn (1921-2016).

Glenn entering his spacecraft, Friendship 7, prior to the launch of Mercury-Atlas 6 on February 20, 1962.

In 1962, Glenn became the first American astronaut to orbit the Earth, putting the US on equal footing with the Soviet Union in the space race. Thirty-six years later, Glenn was diagnosed and successfully treated for glaucoma before his last, historic 1998 trip into space aboard the shuttle Discovery. Aged 77, Glenn was then the oldest person in history to reach space: a record which stood until 2021, when 90-year-old Captain Kirk actor William Shatner joined Jeff Bezos’ Blue Origin space flight.

“I’ll never forget the sight of Earth as I looked from my Friendship 7 Mercury capsule in 1962 or 36 years later from the space shuttle Discovery,” said Glenn during a 2002 glaucoma awareness campaign. “I might not have seen such sights if a simple, quick and painless eye exam had not caught my glaucoma in time.”

John Glenn 1921 - 2016. Credit NASA, 1998