Eyesight and Intelligence?

This article discusses recent studies that purport to show people with glasses are smarter than people who don't wear glasses.  Data consumer beware: Correlation is not causation.

What if people who have spent years in school have worse eyesight from reading so much?

What does it mean to say that 45 other genetic traits are less likely to be related to myopia than level of education?  How are each of those traits related directly to education levels?

I haven't seen the underlying studies which may well answer these questions, but you should think hard when you see an article like this about causality.

One other note: the second part of the article is about subjective perceptions of people who wear glasses.  I also note the sponsor is an optometrist association.