A journey into space is currently just the preserve of a small group of astronauts – but commercial space flights are looking increasingly likely in the next five to 10 years. The implications for optometry might at first seem as distant as Mars itself, but NASA has recognised for some time that space flight affects vision and causes structural change to eyes – including the flattening of the posterior globe, and changes to the optic nerve and retina (American Academy of Ophthalmology, 2013). Dealing with this remains a top priority for the NASA space medicine research team.

The problem was identified even longer ago – John Glenn, the first American to orbit the moon in 1962, carried in his capsule a pair of vision-sharpening “space anticipation” glasses, which had a stronger prescription than normal. The International Space Station (ISS) now provides astronauts with adjustable-focus glasses that eliminate the need for bi-and tri-focal lenses. These Superfocus glasses have a conventional lens at the front, a flexible lens at the back and a dial to focus (Warren, 2011).