Tossed and turned all night long

We have been trying medicine after medicine for the past year and have had no success stopping the seizures. He is not responding to any other medicine. We are down to considering Sabril or looking into other surgical routes (VNS or otherwise). I'm having a hard time considering Sabril becasue of the possibility of vision loss. My son is almost 4 and is relatively close to his developmental age except for his speech. I'm worried about his vision and later in life. I believe that some day he will be able to drivee. A HUGE freedom that I don't want to take away from him. Even if he never talks, driving is something that every teenager dream of. I don't know that I want to take that chance of taking that away from him when there are other options that have side effects that might be less severe. Still doing my research and weighing all the options. I can't thank everyone enough for all their help/input/encouragement!!!!!