You could be having a stroke. When I close my eyes, I see moving patterns and stuff, but flashing lights... no. Check this out: http://www.richmondeye.com/eyehealth_floater.asp
He might be hiding something or there might be something about his past that he isn't happy with or was difficult for him to handle. Give him time. He'll come around eventually. Holding everything in will catch up to him sooner or later.