"Solo lui ha una visione delle cose diversa."
Traduzione:Only he has a different view of things.
Either works, depending on how you choose to speak. As for "vision" being accepted, while everyone agrees, I think it's an over-italianization and shouldn't be, as I've never heard anyone say "vision" instead of "view" in English for this type of sentence, whereas in Italian that's the word you would use ("vista" wouldn't make sense here). That said, so long as people understand that when "vision" is used in this sentence the meaning is strictly -view-, then it's fine I suppose.