For Gatsby, this light represents Daisy, his lost love; in the wider context of the book and its arguments about the American Dream, the green light can also be seen as symbolizing money, success, and the past. In this section, the eyes seem to represent the superficiality of wealth and fame, as the once-majestic advertisement suffers under the inevitable onslaught of weather.
The American dream states that people can work themselves up "from rags to riches" by hard work. To dream is to believe in the existence of the limitless realm. However, the American Dream didn't last forever.
To dream is to be consumed by the passion and beauty of life, for although a dream may never become a reality, the true substance of a dream is its place in the heart.
Gatsby still feels a desire to fulfill his final dream of finding a true love. Hope, perseverance, hard working ambition and adventure are some of the characteristics of the American Dream.