The relationship between blindness and madness can also be seen in the abundant figurative language that links the two, often ironically. When professing her love for her father, Goneril says her love for him is “dearer than eyesight” (1.1.56), and shortly afterwards, when Cordelia refuses to play this “love-game,” Lear says to her, “Hence and avoid my sight” (1.1.125). Kent then tells Lear after the King banishes him, “See better, Lear, and let me still remain / The true blank of thine eye” (1.1.160). Responding to Kent, Lear swears by “Apollo,” known as an archer for being clear-sighted (161). Lear goes mad because he is “blind”—he does not see, understand (as the other responder clearly explains); Gloucester loses his sight literally because of his friendship for and loyalty toward the mad Lear, acting as a kind of doppelganger to him. Studying the pattern of language in relation to blindness and madness shows the structure of the double plot that shapes the themes of the play.
The madness of Lear and the confusion in his mind represents the chaos of Lear's kingdom and the hidden wisdom that Lear never learned as a king. England is in chaos because Lear misjudged the love and loyalty of his daughters. He then goes from being figuratively insane to being actually insane, and Lear learns humility when his madness strips him of his royal trappings, realizing he's been oblivious to the basic realities of mankind. It is only through his madness that he realizes how foolish he has been to betray Cordelia's love for him.
Gloucester's physical blindness symbolizes the figurative blindness of both Lear and Gloucester. Only when Gloucester goes blind and Lear goes mad do they realize how wrong they have been about their children. Both men have been blinded to the truth of their children's love and loyalty. They banish their loyal children and make the wicked children their heirs.
Madness and blindness in King Lear are, to put it "mathematically," inverses of each other. The more insane the character gets, the less blind they become. Both Lear and Gloucester are blind to their situations, that they have cast aside their faithful children and awarded their disloyal ones. However, as the wheel turns, as Lear has been cast into the storm and as Gloucester gets his eyes plucked out, after each has fallen into the pit of insanity are they metaphorically able to read their true situation. Physical blindness leads to figurative clarity.
And the Hubris dhanasekar spoke of, is the Hamartia which runs throughout the play.
The Characters' Hamatria - fatal flaw - is their blindness which for Lear is caused by his arrogance, stubborness, madness. For Gloucester is caused by his Naivety and Blind-trust. Both of which lead to errors of judgement - as they are blind.
Their metaphorical blindness is a result of Hamartia, but the physical blindness of Gloucester and madness of Lear make them see clearly for the first time.
well there you are. there is a connection between the madness of lear and blindness of earl of gloucester. both of them are full of hubris (i.e pride)and this ends their fate to a fatal end.