I don't know if anyone else has this problem, but when I use dark vision it only works sometimes not all the time. Dark vision is sopouse to show feild of vision of your enemies at level 1. Level 2 dark vision when you upgrade from level 1 dark vision shows your enemies feild of vision, see them through walls, and also shows security gear through walls. Wall of light, sound alarms,....etc. Also shows hidden objects you can use to open hidden rooms and shows rats. But for some odd reason when I use dark vision it only works sometimes. It gets annoying when I use it and I think an enemy is not around the corner and they are really there. So if anyone is having the same issue or knows how to fix this please let me know I apperciate it.

I know Issue is spelled wrong

I find that it's range doesn't make much sense at all. I can sometimes see objects such as elixers from halfway across the map, but cannot see wires/enemies that are 30m away.

It actually makes it pretty useless as an upgrade.