I get what you are saying.

However I guess I was referring to all healthcare system in the US. I believe all over the Europe kid would be tested for free, every year, mandatorily. If eye correction is needed one would be supplied. So study like this wouldn't even be possible. Of course maybe some minimum payment would be needed, parents involved, etc. etc. But these are only details.

However the problem itself is not a problem of neglectful parents. It is a problem of healthcare system/educational system and society as whole.