Waiting at thraffic lights, or sitting at the window seat of one train looking into another parked train, when---all hell breaks loose. My foot hits the brakes of my stationary car with such force, my hands clutching the steering wheel in a white knuckle grip, head spinning!!! Same in the parked trains, gripping the seats and lurching forwards. Stomach churning. Wot Visual disturbance has caused this and why? Maybe its a by-product of day-dreaming, and suddenly becoming aware of movement, but why?? westwind.