noun
narrowing of visual field; tunnel vision
Medical or literal sense: restricted field of vision. Also used figuratively for narrow-mindedness or lack of broader perspective.
緑内障が進行すると視野狭窄が起こることがあります。
As glaucoma progresses, narrowing of the visual field can occur.
彼は自分の意見に固執して、視野狭窄に陥っている。
He is stuck in his own opinions and suffering from a narrow perspective.