An optical device includes: a first substrate; a second substrate disposed opposite to the first substrate; a first conductive layer disposed on the first substrate, wherein the first conductive layer includes a first surface and a third side surface connecting to the first surface; a second conductive layer disposed on the second substrate; a sealant disposed between the first conductive layer and the second conductive layer and having a first side and a second side opposite to the first side; a liquid crystal layer disposed between the first conductive layer and the second conductive layer and locating at the first side of the sealant; and a barrier layer disposed between the first conductive layer and the second conductive layer and locating at the second side of the sealant, wherein at least part of the first surface and the third side surface are not covered by the barrier layer.