I'm not sure if it is a different type of neuritis, or whether some doctors call it one thing and others call it the other. I've had to change neuros several times (like 5) because we've moved states from time to time, and I've been unlucky enough to have ON about 4 or 5 times in each eye....never both eyes at once though. Some of my neuros have referred to it as Retrobulbar Neuritis, while others have called it ON.....all have treated it the same.