I didin't know how to phrase it bette, so sorry about the vague title. In a post in r/science an user claimed that ancient cultures used constellations to determine the vision of someone. If one could see all the stars of a particular constellation it was considered that he had good vision. Other user claimed that it was a practice of native americans and another that the romans did that. It seems plausible but is it true?
So the second-to-last star in the handle of the Big Dipper is actually two stars, Alcor and Mizar. Supposedly, Roman army recruits who could see Alcor (the dimmer of the two stars) were eligible to become archers.