Imagery is figurative language or vivid description that shows the reader rather than just tells the reader what something looks like. In this line, the speaker is showing how the clouds blocked out the sun. This creates a sad and depressing mood which is correct for the subject of the poem this line is from.
A metaphor is a comparison between two unlike things without using like or as. There is nothing being compared in this line. A simile is a comparison between two unlike things using like or as. There is nothing being compared. Personification is giving non-human things human-like traits. The line talks about eyes, but it is literally talking about the eyes of people saying that they can't see the sun because of the clouds.
