Your body's natural night vision, walk into a forest pitch black and close your eyes. As you adapt you will be able to see slightly in the night that is your night vision have someone turn on a flashlight doesn't even need to point at you and then turn the light off and you go back to being pitch black blind until you're adjust which can take a bit. Red light won't take away that night vision but unless it's a back road every mother fucker with their overly bright headlights and high beams in 24/7 will blind you anyways.