When Desdemona asks to be allowed to accompany Othello to Cyprus, she says that she “saw Othello’s visage in his mind, / And to his honours and his valiant parts / Did I my soul and fortunes consecrate” (I. iii. 250-252). Othello’s blackness, his visible difference from everyone around him, is of little importance to Desdemona: she has the power to see him for what he is in a way that even Othello himself cannot. Desdemona’s line is one of many references to different kinds of sight in the play.
Earlier in Act I, scene iii, a senator suggests that the Turkish retreat to Rhodes is “a pageant / To keep us in false gaze” (I. iii. 19-20). The beginning of Act II consists entirely of people staring out to sea, waiting to see the arrival of ships, friendly or otherwise. Othello, though he demands “ocular proof” (III. iii. 365), is frequently convinced by things he does not see: he strips Cassio of his position as lieutenant based on the story Iago tells; he relies on Iago’s story of seeing Cassio wipe his beard with Desdemona’s handkerchief (III. iii. 37-440); and he believes Cassio to be dead simply because he hears him scream.
After Othello has killed himself in the final scene, Lodovico says to Iago, “Look on the tragic loading of this bed. / This is thy work. The object poisons sight. / Let it be hid” (V. ii. 373-375). The action of the play depends heavily on characters not seeing things: Othello accuses his wife although he never sees her infidelity, and Emilia, although she watches Othello erupt into a rage about the missing handkerchief, does not figuratively “see” what her husband has done.