At present, three-dimensional (3D) display technology is attracting considerable attention. However, the added binocular depth introduced by stereoscopic 3D technology may not only provide viewers with an entirely different and enhanced viewing experience, but also with visual discomfort and visual fatigue. These problems, besides being related to the health and safety of viewers, have recently gained increasing attention because they significantly impede viewing experience. State-of-the-art studies on visual discomfort related to three-dimensional television (3DTV) are introduced. These studies include those on 3D display technology, the main causes of visual discomfort, subjective assessment measurement methods, and objective psychophysical prediction. This work is relevant to the industry as it suggest ways to prevent visual discomfort when producing 3D displays or shooting 3D videos.