A light emitting device includes a plurality of light emitting units and a first light adjusting structure disposed on the light emitting units. The light emitting device provides a first viewing-angle of a first quantity of the plurality of light emitting units when the first quantity of the plurality of light emitting units is turned on, and the light emitting device provides a second viewing-angle of a second quantity of the plurality of light emitting units when the second quantity of the plurality of light emitting units is turned on. The first quantity is less than the second quantity, and the first viewing-angle is less than the second viewing-angle.