You're saying that your vision isn't affected? Prove it. (Driving is not like playing a video game; you have to focus on things that are near and far, and you have to be able to rapidly shift between them). If you smoke (weed or cigarettes) in your car, the film that the smoke leaves on the inside of the windshield affects your safety if you don't clean it off often enough.
You're saying that your reactions to what you seeing are not impaired in any way? Prove it.
You're saying that your judgement is not impaired in any way? Prove it.
Hint: You cannot be part of the proof. No I, me, or my.