Light modulating device

A light modulating device is disclosed herein. In some embodiments, a light modulating device includes a light modulation film layer, wherein the light modulation film layer includes a first substrate, a second substrate, and a liquid crystal layer, wherein the liquid crystal layer is disposed between the first and second substrates, wherein the liquid crystal layer and is capable of implementing twisted orientation, and wherein a K value is in a range of 0.15 to 0.4. The light modulation device can stably maintain designed optical properties even after an encapsulation process in which a pressure is applied, such as an autoclave process. The light modulating device can also stably maintain the orientation state of the light modulation layer while effectively securing adhesive force between upper and lower substrates.