The U2 front man suffered terrible injuries following a bicycle crash five months ago and says he won't know if he is able to play guitar again for at least another year.
He told the New York Times newspaper: "It feels like I have somebody else's hand. But they say that nerves heal about a millimeter a week, so in about 13 months I should know if it's coming back," he said.
"The shoulder's better, the face is better. But this [his arm] is the hard bit because I can't play guitar."
The 'With or Without You' hit maker previously admitted he would "very much miss" it if he was unable to play the instrument after being fitted with a titanium elbow following the crash, which took place in November in New York's Central Park.
He wrote at the time: "Recovery has been more difficult than I thought ... As I write this, it is not clear that I will ever play guitar again. The band have reminded me that neither they nor Western civilization are depending on this.
"I personally would very much miss fingering the frets of my green Irish falcon or my (RED) Gretsch. Just for the pleasure, aside from writing tunes. But then does the Edge, or Jimmy Page, or any guitarist you know have a titanium elbow, as I do now? I'm all elbows, I am. (sic)"