I've been using serzone, and then nefazodone, for the past eight years. It was the only thing that helped with panic attacks and insomnia, that I now know were caused by hyperthyroidism. I am beginning to very slowly wean off. But, when I first started using Serzone, one of my biggest side effects was vision. I would get intermittent blurry vision. Also, I would experience visual trailers. This eventually went away. I do have to say that discontinuation must be done very slowly, and is no picnic.