The blind aren't continually attacked by folks, hence I wouldn't think that temporary blindness can be held as a legitimate claim for defensive action, in and of itself. As part of an attack, though, it could certainly be seen as a tactic to gain advantage, sure.
You and I use flashlights at night to identify folks, as do police during night stops of folks. Those aren't aggressive/assaulting actions. They're hardly criminal, by themselves.
I know that mere shining of a laser into the cockpits of airplanes is taken extremely seriously by law enforcement. But then, a manually-controlled plane all of a sudden bereft of its pilot is, in and of itself, a materially violent act, in a way that mere temporary blindness while walking on the ground would not be. At least, that's the way my non-attorney mind sees it.
Uncertain of case precedent involving such "blinding" tactics. My guess is that, at best, it's merely recognized as a factor for the underlying crime itself: the robbery, rape or murder in question.