Originally Posted by ricocarlos
I don't care about battery life or eye strain. I just like the ability to control everything my Paperwhite does. I'd like to be able to disable the light completely, and I'd like to be able to turn off the magnet sensor as well. No medical or economic reasons for this at all. I would just like complete dominion over my e-reader.
You can't disable the magnet sensor. You can however turn the light off by using the magnet sensor as in Turn Off Frontlight W/O Jailbreak
. For other ways to turn the light off, check out post #1, #6, and #62 in the thread that the linked post is in (all those require jailbreak and more).
For total dominion you have to get an open source ereader with documented and readily available source code. Good luck on finding one.