What is the significances of Gloucester's going blind and Lear's going blind?

Gloucester’s and Lear's blindness are metaphorical and symbolize the things they have in common....... most importantly their refusal to see or accept the truth (maybe the worst kind of blindness). Each of these men has children who are loyal and disloyal, and both of them banish the children who truly love them, only to embrace and make heirs of the wicked. Physical blindness is the predecessor to truly understanding their mistakes; the fact that in the end they are together to commiserate these mistakes is a true bit of irony.