To any newcomer of the thread:
One great idea is to treat your forgetfulness as an opportunity to get rid of a few ill-advised changes 5th edition made.
If you reintroduce low-light vision to the game, lots of issues resolve themselves almost as if my magic!
Not only can you remove the disadvantage to Perception you keep forgetting about, but you can also reduce the number of PHB races with Darkvision by three: give Elf, Half-Elf and Gnome low-light vision instead of darkvision.
This reduces the tendency of city slicker DMs to have underdark races carry light in patrols (a big nono). It also allows forest animals to hunt prey at larger distances than 20 meters.
The best thing about this houserule suggestion is that it's proven to be functional and easy to use!
(Indeed, D&D itself used it for a whole decade. Eager to reduce conditions and states, unfortunately 5E removed it without thinking it through. Good news is - it's very easy to rollback the changes.)
Anyway, just a suggestion
Cheers!