Of course you are assuming that his vision is correctable.  I'm assuming
that he went to an eye doctor, and that's how he found out what his
vision was.

If his eye doctor said he should get glasses, at least to try, then I
concur.

I went to my OD a few weeks back, to see if I should wear glasses or
contacts.  He said that it was my decision.  Since three different eye
doctors have told me that I need to wear them, not for correction but
for protection, since my vision in one eye isn't good, after two weeks I
decided to get them.  With the insurance, it was all of US$3.00, so it
wasn't the money.  They do help my vision, although I often forget to
wear them.