Don't avoid what the doctor recommends. He is probably more likely to recommend vision therapy and eye exercises and maybe an eye patch on the strong eye for a while, than glasses, but if he does recommend it don't assist your son to avoid wearing the glasses. The serious question is why it came on so suddenly. Don't gloss it over with "the working eye will do the work of the weak eye," he needs correct depth perception and there are other issues too. Get him to a good opthamologist or diagnostic optician.
It wouldn't be anything to do with puberty.
I think an opthalmologist would be a better option for your son to be seen,they will be able to tell if its just a vision issue or if its something more serious.I am saying this because my daughter also had some vision issues that they didn't take seriously until she was seen by an opthalmologist.