why i cant turn off my key light as my wish ?

[WPCentral Question]

i have nokia lumia 920 with windows 8 and i update it to 8.1 after the os update .I can't turn off my key light .i am feeling very difficult while watching the video plz help me...

 

[gpobernardo]

The back-lit keys will be active whenever the screen is active in a "dark" environment. The keys will not be back-lit if you move to a sufficiently bright environment, courtesy of the ambient light sensor of your phone.

 

[Joe920]

These lit keys are so annoying that it should be an option in Settings, and they should be accessible via API. You used to be able to turn them off using battery saver, but apparently launching device hub even once breaks this permanently.