A transmittance-variable film and the use thereof are provided. The transmittance-variable film can be useful in switching between a clear state and a dark state and reducing a difference in contrast ratio between left and right viewing angles, thereby securing excellent bilateral symmetry. Such a transmittance-variable film can be applied to various applications including various materials for buildings or vehicles requiring the control of transmissivity, or eyewear such as goggles for sports or experiencing augmented realities, sunglasses, helmets, etc.