An input system and an electronic apparatus with novel structures are provided. An electronic apparatus whose setting can be changed even when both hands are full is provided. An input system and an electronic apparatus including an imaging device having a function of taking an image of eyes and a detection device having a function of detecting a change of the shape of the eyes from data obtained by the imaging device are provided. Settings are changed in accordance with the change of the shape of the eyes. The settings are changed by a different method from a manual method and the change of the settings can be reflected in display.