This sounds awkward. Would it not be better to say "he does not want glasses"?
You can say "He does not want glasses," or "He doesn't want glasses." Just a different syntax.
"He is not wanting glasses" is exactly how you'd say this in Scotland.
In English (as influenced by Gaelic syntax).
In English 'he is not wanting glasses' would normally mean that he already has a lot of glasses, while 'he doesn't want glasses ' would mean that he has no wish to have them, and probably hasn't got any
There is a difference in Gaelic between things that happen in the moment and more general continuous thinks. Hence the difference.