I don’t know, there could be all sorts of confounders there. Like maybe poor eyesight means you’re not as good at sports which means you tend to focus on more studious hobbies like reading.
Or maybe reading and spending time inside tends to ruin your eyesight. Or maybe it does, but only because it takes time away from active pursuits like sports!
Does anyone have pointers to research that teases out the causes and effects here?