A wearable device, which comprises: a ring-shaped case having an opening part formed in the middle thereof; a projector mounted at one side of the case and outputting an image; a lens part adjusting the direction and the size of the image, which is projected from the projector, so as to project the image; and a control unit for adjusting the projector and the lens part according to an image signal, can deliver visual information to a user wearing the wearable device even without a separate display unit by outputting the image onto the hand of the user.