What self defense situation would you need a light? A light is certainly good if your going through a building like a cop would do sweeping the area...but self defense??? If there is a threat right in front of you I'm pretty sure your going to know it whether you have a light or not. If you need a flashlight to identify your target your probably not in a self defense situation and can get yourself out of it. The only situation I can think of is if you hear a noise in your home and you go to investigate, but that's not self defense. That's you investigating making sure your not getting robbed and protecting your property.
Ensuring what's at the end of your muzzle.