http://en.wikipedia.org/wiki/Houston_(singer)
He was reportedly dealing with emotional troubles and it came to a head one night in early 2005 while he was on tour in London. Before a show, Summers suffered an emotional breakdown and reportedly tried to commit suicide by jumping from a window, while under the influence of PCP. When people in his entourage stopped him, he was restrained and locked in a first floor room. While in that room, Summers then proceeded to gouge his left eye out in a fit of rage.[2] Shortly thereafter, Summers was taken off tour, and returned home to his family in Los Angeles. Houston is now completely blind in his left eye as he has a glass eyeball. He is currently a vocal activist against inner prison rape, causing many to wonder if he was a victim himself.