I experience something of this sort, but not in nearly as harsh a form as most of the people who have posted here have expressed.
For me, yes the images are visual, but they are not something I "see" they aren't like flashes across my vision, but rather images that are clearly in my head. which may help to keep them from being as frightening to me.
I have always thought in a mixture of visuals and language along with vague feelings or impressions of things, but this violence does not come to me in the relm of words or in that of actual violent feelings, or fearful feelings.
But they do come in the form of pictures, sometimes moving but always very brief usually either the inflicting of an injury or the injury itself.
usually self inflicted, though on occasion I have had images of doing violence to others.
At one point in time in my life I considered this being "triggered" if something occurred that "made"(= forced somehow, being not my fault of course...

later when I gave up SI I came to realize that these feelings or images did not need to be associated with any action on my part or desire to execute what I had "seen".
So now when I see these flashes, or think about violent things (in images) for a moment I am able to let them pass as simply a thought that is neither good nor bad, nor even neutral, but simply exists as it is.
I have studied a number of philosophies and religions, and am currently studying buddhism .. though I am not buddhist. but something that I learned from that religio-philosophy is that we do not have to react to our thoughts, we can simply let them be as they are. That thoughts don't necessarially come from anywhere or need to go anywhere.
these images are only "triggering" if we let them be so.
of course not "letting" them be triggering is something that would take some time and work and concentration, but ultimately, for me, it was worth it.
I don't know if this would work for someone for whom these images were more intense, as I said mine were ... startleing, jarring, disquieting, but they did not evoke fear in me.
thanks for the opportunity to talk about this, it wasn't something I was ever really able to word so directly before.


[slint]