I think that eyes might be repeated to reflect how different sets of perceptions clash in the narrative. The eyes of the revolution is how Valentin perceives the world. These eyes perceive the unjust actions of the government and see the injustice present, causing the need to envision what should be from what is. Interestingly enough, these eyes succumb to the morphine based vision that is about as far off from the pace of the revolution as possible. It is this vision that allows peace to be present in Valentin, although he has abandoned the vision of the revolution in his last moments of life. In contrast, the "eyes" of the government are always present, seeking to gain more information and intelligence about the revolutionaries, only to crush them. These eyes are also present in how the prison officials use Molina to gain information about Valentin. These same eyes are what follows Molina to his death after his release. At the same time, Molina's eyes seek to construct a reality where there is beauty and love, eyes that envision this reality from films that have been seen and life that seeks beauty and the appreciation of it. These eyes are what perceive reality as a pursuit of indulgent drama and maudlin sentimentality, yet are also the eyes that experience a revolutionary's death, shot on the street without any fanfare and little drama.