Blindness as Sight
One of the central motifs and ironies of King Lear is the prevalence of blindness in the play's plot. Gloucester is the character who most obviously fulfills this role, as he is physically blinded by Regan and Cornwall in the middle of the play. Only after Gloucester loses his eyesight, however, does he come to see things as they actually are. The play ironically suggests that knowledge and truth are not dependent on what is before one's eyes.
Madness as Clarity
Similar to Gloucester's trajectory, Lear experiences a shift from a figurative blindness – in his misjudgment of his children and himself – to self-knowledge by the end of the play. Ironically, however, this change stems from Lear's descent into a near-mad state, when he can no longer communicate clearly and is crippled by old age and vulnerability.
The Wise Fool
In an ironic convention of the period, Lear's fool is arguably the wisest character in the play. Employed by Lear for entertainment and more often ridiculed than celebrated, the fool is not a character one expects to carry great insight. However, early modern English theater often upended this expectation and endowed fools, clowns, and other characters meant for comic relief with surprising moments of knowledge and thoughtfulness. In King Lear, the fool is the one who warns Lear about dividing up his kingdom, likening it to a cleaving of the crown itself.
Poor Tom
Poor Tom – or Edgar in disguise – represents a major instance of dramatic irony in the play. The audience is aware of Edgar's disguise, but Edgar uses the Poor Tom persona to hide from Cornwall and to remain anonymous to his own father, Gloucester. When Edgar is in his Poor Tom disguise, the blind Gloucester is caring and paternal toward him, suggesting the value of their father-son bond despite the changes they have both endured.
