Motion sickness is caused by the information differences between the vestibular, visual, and bodily senses. Window curvature and sight blurring are considered to influence eyesight information. This study experimentally investigated the influence of motion sickness by window curvature and sight blurring changes in the response to multiple combinations of conditions. The result indicated that a view from a car window with a vertical wave on the window surface was likely to cause motion sickness. Conversely, visual distortion in the horizontal direction could be acceptable to passengers. The study also proposed the minimum design requirements for car-body shape based on the results.