Justin Bieber was knocked unconscious yesterday after he plowed headlong into a glass wall backstage during a concert in Paris. TMZ says:

Justin… said he was performing on stage, and in between songs he walked backstage and hit the glass. He says he was disoriented, but went back on stage and finished his set.

As he walked to his dressing room he passed out cold, for around 15 seconds. Doctors say Justin suffered a concussion but he’ll be ok.

This is not the first time Justin was on the losing end of a battle with a glass door (see video below). So I guess you could say he can’t see through glass… or through “girlfriend” Selena Gomez. Their love is about as real as his highlights.