According to Julian Lennon, U2's Bono's vision--which the singer/activist has said is the reason he wears his trademark shades--is worsening. The Irish Daily Star quotes Julian as saying: “Bono actually has a condition with his eyes. I don’t know the exact issue but the brightness of the sun hurts them and it’s a deteriorating issue.” And Julian said: “It’s part of his image so in some senses, it was lucky, but not really, of course. Maybe it’s part of his process now and without the sunglasses, he can’t be Bono.”
In 2005, Bono revealed that the sunglasses, which he started wearing as part of his "Fly" character on stage in 1991, are now medically helpful to him. He told Rolling Stone at the time: “If somebody takes my photograph, I will see the flash for the rest of the day. My right eye swells up...It’s part vanity, it’s part privacy and part sensitivity.”