Eyes have three symbolic meanings in the play. First, eyes are symbols of the vision needed to see the future. With the initial exception of Electra, all the Argives have "dead" eyes because they can only look towards the sins of their past. Orestes's eyes are bright because he looks ahead towards the future, unhampered by his past. Second, eyes symbolize judgment. Electra is afraid of how others will judge her. As a result, she always notices everyone's eyes. In Argos, where every person expects to be observed and judged by his or her neighbor, everyone fears the eyes of others. Those who cannot freely impart meaning on their lives allow others to interpret their lives for them through the judgment in their eyes. The looks of others enslave us if we allow others to impose their moral standards on us. Jupiter, whenever he gives someone an order, forces that person to look him in the eyes: as the supreme judge, he controls human beings with his eyes, the symbols of judgment. Third, the symbolism of eyes reminds the audience that it is watching, with its eyes, a dramatic performance, and this conscious reminder of vision suggests that it is possible to go beyond the purely visual presentation of the play and to put the play's values into action in real life.
Stones recur repeatedly throughout the play. They are symbols of nature. Unlike human beings, who have the freedom to give meaning to their lives, stones are inanimate objects that have no meaning until someone imposes meaning on them. Jupiter has powers over nature and twice demonstrates his power over stones, first when he causes a stone to roll away from the cave of the dead to silence Electra and then again when he causes light to flash around the stone in response to Orestes's request for a sign. Since Jupiter can only control stones but not people, he seeks to reduce all human beings to the level of stones. He wants to impose order on humanity that will allow him to impose meaning on human beings from above. So long as people fear him, he has power over them because they worry only about how he interprets their actions. Stones are a contrast to human existence, but human beings can also be reduced to stones.
The flies were sent to Argos by the gods fifteen years before the action of the play when Aegistheus and Clytemnestra murdered Agamemnon. The flies serve as a perpetual reminder of this original sin, biting the Argives to help them repent. When Orestes and Electra kill their mother and the king, the flies turn into the Furies, the goddesses of remorse. The Furies live to punish sinners, but they have power only over those who feel remorse for their actions. Orestes is immune to the power of the Furies. Electra, on the other hand, willingly surrenders herself to them when they promise that the physical pain they cause her will make it easier for her to tolerate her repentance.