Like one time I had a phenomena where I was just casually walking at night and my visualitory facuialties just narrowed to a say roughly 15% acuity in my front gaze so very selective. Also when my eyes were looking forward they also sorta trance locked forward. I had hardly any control to seem to migrate their solid stare.
This happens to me fairly often. Generally it happens when I'm extremely focused on something, such as working on something small or intricate, driving for long periods, or looking at something intently (trying to determine a buck's antler size, beautiful woman
I have also experienced it in high stress situations and have experienced auditory suppression as well, though nothing I would describe as "tunnel hearing".
In crimes - it's called weapons focus effect. Witnesses or victims focus and remember more details of the weapons than attackers.
Argued is due to the weapon being uniquely focused on or just being something unusual in the scene.
I have read about this. There are reports of witnesses describing a pistol as huge and when recovered it being a tiny .25 or .22 mouse gun. Apparently there are also a surprising number of hand/weapon hits in gunfights due to the phenomenon.