Light and darkness are important symbols in Endgame. In the post-apocalyptic world, with the rest of humanity seemingly dead or dying, the fading light which Clov glimpses through his kitchen represents the fading life in the world. Everything is gray in this world, with the optimism and hope of the once-flourishing society dimmed by whatever catastrophic event has led the characters to this point. The weak light reflects the state of the world. The most pessimistic of all these characters is Hamm, whose relationship with light is defined by absence. Hamm is not only blind, but he wears dark glasses over his eyes. Even if he could see, the hopeful light of the outside world could not reach him through the dark glasses. Hamm is fumbling around in the dark, having relinquished the light of the world in a literal and figurative fashion. Nevertheless, he cleans his glasses out of habit, another of the repetitive, futile acts that make up the texture of life for these characters.

The absence of light or the withholding of light also has important symbolic values. One of the few criticisms that Clov dares to direct toward Hamm is that he has withheld light from a needy person.