And it’s not, as so many people thought, because he is so famous that he doesn’t want to look people directly in the eye.
The U2 frontman actually suffers from glaucoma – a build up of pressure on the eyeball which can damage the eye’s nerves – and told Graham Norton he’s been receiving treatment for the condition which can lead to blindness.
“This is a good place to explain to people that I've had glaucoma for the last 20 years,” he explained.
“I have good treatments and I am going to be fine. You're not going to get this out of your head now and you will be saying 'Ah, poor old blind Bono'.”
Earlier this week the singer apologised to the public after their new album Songs Of Innocence was downloaded onto half a billion iTunes accounts across the globe.
He said the decision was down to a “drop of megalomania, touch of generosity, dash of self-promotion and deep fear that these songs that we poured our life into over the last few years mightn't be heard.”
Well they certainly have now.