When things get so dark that you can't see more than a 10 feet in front of you without a light source, the infected don't seem to have any problems chasing after you as your character tries to escape. Did I miss a change in the back story for this game? I didn't read about any change from them going from "infected" humans to beings with night vision so why can they see in the dark when we can't? I get that expecting their behavior at night to be different than during the day would require some coding and that isn't going to happen any time soon, but why simulate a dark environment where your eyesight doesn't adjust to the lack of light? You should be able to make out some shadows at a reduced distance unless you are in a room without windows and with the doors closed. Being able to see minimal details in the dark should be part of the fun as you try and sort out if that shadow moving by the police station is a player or an infected.
A couple of days in a row now I've had well equipped characters die by zombies that I could not see without a light source. Yes, I had to drop a torch/flashlight/flare etc to use a gun (because having a torch in one hand and a pistol in the other is totally unrealistic! ) and had to run/fight off a horde that were only visible when they were close (~3 meters) to the light. When I tried to back off or run away they had no problem following me and killing me even though my character couldn't see where they were going let alone an outline of one of the infected giving me a shot to the head.
Cheers!