expression, noun
empty eyes; thousand-yard stare; blank gaze
Describes a lifeless, expressionless look, as if the person has lost all emotion or energy. Often used for someone who is exhausted, depressed, or emotionally drained.
長時間の会議の後、彼は死んだ魚の目をしていた。
After the long meeting, he had the eyes of a dead fish.
彼女の死んだ魚の目を見て、何かあったのかと心配になった。
Seeing her blank, lifeless eyes, I worried that something had happened.