In Shakespeare's Sonnet 18, the phrase "Sometime too hot the eye of heaven shines, / And often is his gold complexion dimm'd" is a metaphor that refers to the irregularity of nature's beauty. The "eye of heaven" is the sun, so when it shines too hotly, it can be uncomfortable or even harmful. Likewise, the "gold complexion" of the sun can be dimmed by clouds or weather, making it less brilliant than it would normally be. The speaker suggests that natural beauty can sometimes be hindered by its own excesses or by external factors beyond our control.
