" The lights that surround Gatsby are artificial lights, lit when it is dark out. Rather than the warm appeal that Nick sees in Daisy in daylight, Gatsby's lights are flashy and almost garish against the backdrop of night. They briefly illuminate Gatsby, almost as if to leave an afterimage of Gatsby's flamboyance in people's eyes. When they fade, however, Gatsby is left with shadows that adds to his enigma. In truth, the darkness that shadows Gatsby's presence may be more revealing of his character than the light. Nick first sees Gatsby in person in the dark; through him, as the narrator, that is also the first actual sighting of Gatsby for the readers. On that occasion, he is seen to look towards "a single green light, minute and far away".
While Fitzgerald never explicitly states the purpose of the green light, it holds significance in that it sits at the end of Daisy's dock, across the bay from Gatsby's house. Somewhat unusually, although the green light is an artificial light, with a strong association with Gatsby, it has still stronger links to Daisy. Yet it serves as a bridge between the two, bringing to light the then-unknown history between the two to Nick Carraway. To Gatsby, its significance is relatively evident; it embodies his relationship to Daisy, in the old maxim of 'so near, yet so far'. He seizes on the green light as a symbol of Daisy, almost as if it were a guiding light to her. That may indeed be its practical purpose, given its location on a dock; but for Gatsby, it is something of a mirage. Like a mirage, it disappears once the destination is reached, and the goal found to be a fantasy and not reality. As Nick Carraway puts it, the "colossal significance of that light had now vanished forever". He mistakes it for something it is not, just as he misinterprets Daisy and her actions. Perhaps Gatsby does recognise the deception when he realises that Daisy is once again with him, but not the Daisy he imagined would unfailingly choose him.
