Movement and Darkness
As far as I can tell, there are no rules effecting movement when you can’t see. A blind character can move just as far and just as well as one who can see. I find this rather silly. So I am proposing a house rule until I can find a better one.
If you cannot see (either due to blindness or simple lack of light) you are considered to be in difficult terrain. If you wish to risk it, you can attempt to move at normal speed. However, depending on the terrain and such, I will ask for either an athletics or acrobatics check. If failed, you fall prone, and take half of 1d10 damage.