An embodiment provides a lens comprising: a lens body; a groove placed on one side of the lens body; a plurality of light path conversion units arranged on a first area of the surface of the lens body, opposite to the groove; and a plurality of refraction units arranged on a second area of the surface of the lens body, opposite to the groove, wherein the first area and the second area are arranged opposite to each other with respect to the center of the surface of the lens body.