Gonna bump this one back up. It frustrates me greatly that this request has been made for over a year across many, many places on obsidian and reddit, yet the developers have either completely ignored or completely failed to communicate with the community to implement something so simple as an option saying "enable explored fog of war: yes/no".
I have found countless posts around the internet from people who completely stop playing because of explored fog of war. I've played the game for a few hours on a friend's copy, and I can safely say that i will never purchase a copy unless the change is made, but I will buy it the second it is made. I'm sure enough people agree with me.
I'm aware that fog of war was lightened with one patch, but WHY is there not an option to remove? It would be purely cosmetic. All unexplored areas still black, so there's no "strategic & tactical" advantage anyway. I can see a tree across my entire yard which is much longer than POE's circle of vision, and nope, the tree's not dark...