First, let us assume for simplicity that this discussion does not include any form of night-vision capability.
Most of the instructional material I have presents the conventional wisdom of having either a handheld or weapon-mounted light to first identify – and then engage if warranted – a potential threat.
Some have pointed out to me though, that using a light also makes yourself probably the most easily acquired target on the scene.
Others have asserted that conditions having absolutely no light are very rare, and that better strategies are built around effective use of available light.
Still further, the little bit of low-light shooting I have experienced has been indoors, where having a light superimposed on the barrel exhaust almost instantly clouds the scene after the first shot. Nothing I have ever read even mentions this phenomenon, much less discusses how to cope with it.
So, I’m confused (a common occurence). 
Opinions here are certainly welcomed, but mostly I’m looking for any sources of information (books, videos, etc.) that specifically treat defensive use of light at some kind of meaningful level. This seems like a major issue to me, and I’m surprised it hasn’t been given a greater amount of attention.
Thanks for any help.