Bono's friend has revealed the star's eye condition is deteriorating.  

The legendary U2 frontman has explained that he wears his signature sunglasses because his eyes are sensitive to light.

Bono's friend Julian Lennon has revealed that the singer's eye condition is worsening over time.

In an interview with the Irish Daily Star Lennon explained: ''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.''

He continued: ''It's part of his image so in some senses it was lucky but nor really of course. Maybe it's part of his process now and without the image he can't be Bono.''

Bono has previously spoken about his condition.

He said: ''I have very sensitive eyes to light. If somebody takes a photograph, I will see the flash for the rest of the day. My right eye swells up.''