Depends what kind of flash light and what kind of night vision. If his night vision is infrared, then if a regular flashlight doesn't obviously do anything, but if he's using a infrared light it actually works. If your in a dark room that's has all surfaces and relatively the same temp (infrared is heat vision) a infrared light would help you "see" better. That's my understanding of it, I may have overlooked a technical issue or so. But of this guy above has light amplification Google and a regular flashlight, he'd blind himself, so something is going on different. That's all I'm saying! Love the meme by the way, got my upvote!????