Loss of Judgment and Insight: As Gloucester becomes physically blind, Lear undergoes a metaphorical loss of judgement and insight. Lear's rash decisions, such as dividing his kingdom and banishing Cordelia, stem from his clouded perception of reality. Just as blindness impairs Gloucester's ability to see physically, Lear's emotional turmoil and pride impair his decision-making abilities.
Seeing the Truth: Gloucester's blindness eventually leads him to recognize the true characters of Edmund and Edgar. Ironically, this loss of sight grants him a clearer understanding of people and situations. Similarly, Lear's own suffering and tribulations eventually help him shed his pride and delusions, allowing him to perceive the truths he initially overlooked.
Vulnerability and Dependence: Gloucester's blindness makes him vulnerable and dependent on others, most notably his illegitimate son Edmund. Lear, too, becomes vulnerable as he loses power and authority. His journey through the storm and his subsequent madness expose his need for support and care, emphasizing the fragility of his mental and emotional states.
Moral Blindness: Gloucester's blindness can be interpreted as a consequence of his moral shortcomings, particularly his mistreatment of his son Edgar. Lear's tragic downfall is also rooted in his moral failings, such as his pride, lack of self-awareness, and the banishment of Cordelia. Both characters' blindness highlights the consequences of ignoring moral responsibilities and ethical considerations.
Redemption and Transformation: Gloucester's suffering ultimately leads to his redemption. After realizing his mistakes and reconciling with Edgar, he experiences a sense of renewal and spiritual growth. Lear's journey follows a similar trajectory, as his descent into madness and suffering eventually brings about a profound transformation, enabling him to attain a deeper understanding of himself and the world around him.
By paralleling Gloucester's physical blindness with Lear's metaphorical struggles, Shakespeare enhances the play's thematic exploration of perception, self-deception, the consequences of rash actions, and the potential for redemption and personal growth.