U2's Bono says he wears sunglasses because of glaucoma

U2 singer Bono says his ever-present sunglasses are not a rock-star affectation — he has suffered from glaucoma for 20 years. 

The condition — a buildup of pressure that can damage the optic nerve — can make the eyes sensitive to light. 

Bono told the BBC's "Graham Norton Show" that he had the condition, but "I have good treatments and I am going to be fine."

He said people would now think of him as "poor old blind Bono."

He also acknowledged that some people had been annoyed when U2's new album, "Songs of Innocence," was sent unsolicited to millions of people with iTunes accounts.

In comments released Friday by the BBC, Bono said, "We wanted to do something fresh, but it seems some people don't believe in Father Christmas."