As in Oedipus the King, a major theme in Othello is man's inability to reliably distinguish between what seems to be and what; however, this shared theme of "uncertain vision" is treated somewhat differently in Othello than it is in Oedipus the King. Namely, first of all the reason behind the "uncertain visions" and the tragedy that ensue from one another is different in the two plays. In Oedipus it is the unavoidable clutches of destiny that cause the protagonists not to see what is going on behind their backs. In Othello however the reason both for the tragedy and the "uncertain vision" has a name, Iago. .
The second most important reason as to why the uncertainty is treated differently is the fact that Othello due to his temper might be able to see what is happening, but his "hot blood" does not let him do so. Oedipus on the other hand is being utterly objective and is doing all that he can to bring the investigation to an end even though it may have disastrous consequences for him. In other words Othello acts before investigating the issue just a little further and will not listen to reason. .
Oedipus on the other hand is begged both by Jocasta and the shepherd not continue investigating and avoid tragedy but he refuses. This of course raises one of the most important questions regarding the two plays: are Othello and Oedipus different and to what extent? They are both facing situations that are devolving behind their backs and are unavoidably leading to tragedy. However, one of them refuses to see some obvious signs that could avoid the tragedy while the other keeps investigating signs that clearly indicate that a tragedy will happen. Therefore the most basic question regarding this issue is: whether the difference in character or situation that makes the two "uncertain visions" different?.
If ever a tragedy was described that had no other culprit but the destiny or the will of gods, than that is the story of Oedipus.