Because when you are sad and gloomy and depressed, your eyes lose perceptivity.

你悲伤，而且沮丧，抑郁，你的眼睛将失去觉知。

youdao

He became very gloomy and depressed.

他变得非常沮丧抑郁。

youdao

There is a place where the weather stays gloomy and rainy almost all year around and the people who live there get depressed easily due to the weather.

有这么一个地方，那里的天气几乎一年到头都是阴雨连绵、死气沉沉，而居住在那里的人们也因此总是感到郁闷压抑。

youdao

Recent gloomy warnings from the world's biggest chip maker had depressed expectations to a level so low that the market responded with relief.

ECONOMIST: The Fed cuts again