My grandfather, in the army in the 1950s, mentioned that there was an eyesight test by having cadets look at a star and ask them how many light points they saw.

I'm not convinced it was Polaris and its partners, there might have been another star system used as the test. I learned about Polaris being a triple star system years later.

If anyone knows what star systems would had been used as an eye test... I imagine it's something that could be within our eyes limits.

[–] DrinkMonkey@lemmy.ca 3 points 1 year ago (1 children)

Unlikely Polaris. The luminosity difference between Polaris Aa and the other two is 3 orders of magnitude. Mizar and Alcor (the doublet second from the end of the Big Dipper) has been used for centuries as a vision test. If you can see the doublet, it’s equivalent to 20/20 (or 6/6) on an eye chart.