When we’re angry, we use the corrugator supercilii muscles near our eyes to pull our eyebrows down and together. This causes our forehead to wrinkle and squint our eyes. As a result, we significantly cut off our peripheral vision. (Try it.)
In other words, anger literally narrows our vision, cutting off what we can see. Paradoxically, the angrier we are, the surer we feel about ourselves.
It’s a useful metaphor. The less we see the more frustrated we feel. Yet, we can’t see unless we learn to look.
Maybe that is why anger makes us so stubborn. We pick an island and decide to die on it since we can’t see any other useful alternative.