( CNN ) -- There 's a reason for Bono 's ever-present orange-tinted sunglasses , and it 's not rock-star affectation . `` I have glaucoma , '' he told British talk show host Graham Norton . `` For the last 20 years . '' Bono , 54 , was on Norton 's show with the rest of the band , as well as actors Robert Downey Jr. , Robert Duvall and Stephen Fry . Bono 's revelation came after Norton showed a couple of the group 's early photos featuring Bono without spectacles ( and The Edge without his skullcap ) . Noting the difference between Bono in 1980 and Bono today , he asked , `` Do you ever take ( the glasses ) off ? '' The U2 frontman explained that he had excellent vision , but noticed that objects and lights were accompanied by cloudiness and rings -- an indicator of the condition -- `` and it 's not from anything exotic , '' he joked . Glaucoma may lead to blindness , but can be treated with medication or surgery . Bono said there was no need to worry about his health . Explainer : How is glaucoma detected ? `` I have good treatments , and I am going to be fine , '' he said . `` You 're not going to get this out of your head now , and you will be saying , 'Ah , poor old blind Bono . ' `` He willingly put on an oversized pair of aviators and then traded glasses with Downey . `` I look ... cleverer , '' he said . U2 's most recent album , `` Songs of Innocence , '' was released last month as a free download on iTunes , which caused its own bit of news .
Bono tells Graham Norton he wears glasses for his glaucoma . The U2 singer says the condition is a "constant struggle" and that it has affected him since childhood. `` You 're not going to get this out of your head now , '' he said .