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Every hour children spend on screens raises chance of myopia, study finds
(www.theguardian.com)
This is a most excellent place for technology news and articles.
and depending on where they hang out on the internet, figurative myopia too!
But yeah, staring at a close distance for long periods of time tends to lead to nearsightedness in general. However, I've got myopia but not as bad as my siblings who spent less time in front of the screen growing up. Genetics plays a role too, among other factors.