A writing device includes a display panel, a stylus, a transparent first electrode layer and a second electrode layer. The display panel includes a displaying layer and a first light source. The displaying layer consists essentially of a photochromic material reversibly transformable between a first state of an electroluminescent material, and a second state of a non-electroluminescent material. The first light source is configured for emitting light to the displaying layer to transform the displaying layer into the second state. The stylus includes a second light source configured for emitting light to illuminate portions of the displaying layer, thus transforming the illuminated portions of the displaying layer into the first state. The first and second electrode layers attached on opposite sides of the displaying layer are configured to excite the illuminated portions of the displaying layer in the first state to emit light.