I can vouch for this. I have it too, and a few years ago my partner died. I was the one who found her dead, but because I can't remember any visual aspect of it, I'm sheltered somewhat from flashbacks of the trauma. I also hypothesise that it's the reason why I very rarely ever remember dreaming, and this is probably also helpful as I suspect I'd otherwise have nightmares about the event.

It has a double edged effect though: I also can't really visualise her face, and that really depresses me at times because it feels like I'm forgetting her memory (I have to remind myself that I'm not really).