I summed up all the issues with flashlight in this ticket, because I thought it would be useless for me to create one ticket per issue, as I would get a worse chance for devs to look at all the issues (all the separate tickets) regarding flashlights otherwise (by the simple fact that there are many important issues in this feedback tracker never been looked into by devs or staff so they still say "new" or "open").
So I decided, let's fix the flashlight in common, why not?
Also, check that ticket about lens flares http://feedback.arma3.com/view.php?id=21601
And this ticket about light penetration from light sources in Arma 3
http://feedback.arma3.com/view.php?id=4180
On a later stage it would also be cool to implement IR filters for flash light (or just add another flash light which emits IR light instead), but for now let's just start from fixing flash lights in general.