Custom windlight settings
In order to implement vision alterations (such as when the video subsystem is turned off, auxiliary power is enabled, or charging) the controller needs to manipulate your viewer's windlight settings. This means that if you have a custom windlight preset in use, it will be overridden by the region's default windlight. Additionally:
If your vision is still blocked after detaching a controller, put the controller back on and wait a few seconds, then remove it. This is commonly caused by removing the controller while it is still shutting down, although it can also happen due to packet loss (as can a myriad of other RLV-related problems.)
To manually clear windlight alterations in your Second Life viewer:
1. Press Ctrl-Alt-Shift-S to open the Debug Settings window.
2. Search for "RenderResolutionDivisor"
3. Set the value to 1
4. Choose a new windlight preset. For example from the 'Sun Position' or 'Environment Editor' submenus under the 'World' menu.