'Darkened' in the Bible

before the sun and the light, and the moon and the stars are darkened [by impaired vision], and the clouds [of depression] return after the rain [of tears];

in the day when the keepers of the house (hands, arms) tremble, and the strong men (feet, knees) bow themselves, and the grinders (molar teeth) cease because they are few, and those (eyes) who look through the windows grow dim;