You will need to pass a vision test or bring a completed Eye Test Report with you.  You will then surrender your old license along with providing proof of identity.
Will my adult son also need a New York state drivers license if he is only coming here to study at the university?
Is he going to be considered a resident of New York state or is he going to maintain an address of residence elsewhere?
He is not going to claim residency in the state.  His residency will remain in Canada between semesters and after completion of schooling.