"There is some strange thing
toward, Edmund; pray you, be careful...."
See in text (Act III - Scene III)
Gloucester puts his faith in the wrong son, much like Lear trusts Goneril and Regan rather than Cordelia. Gloucester’s family can be seen as a mirror for Lear’s, as both Lear and Gloucester are blind to the characters of their own children. Since the audience knows of Edmund’s ambitious intentions, Gloucester’s faith in Edmund is an example of dramatic irony.
"ah, that good Kent!..."
See in text (Act III - Scene IV)
Gloucester’s appearance and statements provide a good example of irony, because his failure to recognize Kent or his own son Edgar, despite how much he claims to love and value them, shows his blindness. This echoes Lear's inability to recognize Kent, and it provides a literal emphasis to the metaphorical blindness of the old men towards the actions of their children.
"How malicious is my fortune, that I must repent to be
See in text (Act III - Scene V)
Edmund’s betrayal of his own father is the ultimate corruption of the bond between father and child. Thus, Edmund’s breach of this parent-child contract in the name of justice and righteousness is ironic, because the audience knows of Edmund’s depravity.
Came then into my mind;..."
See in text (Act IV - Scene I)
This line is a form of dramatic irony. The audience knows that the madman whom Glocester saw in the storm was actually his son Edgar who now stands before him as Poor Tom. Glocester however does not make this connection, further demonstrating his metaphorical blindness along with his literal blindness.
"Edmund, I think,
is gone, In pity of his misery, to dispatch
His nighted life:..."
See in text (Act IV - Scene V)
This statement is meant to be ironic. Edmund is not going to put an end to his father’s life out of pity but rather to protect his evil ambitions. “Dispatch” in this context means to put an end to.