Various embodiments may relate to a lens for a lighting assembly. The lens includes a bottom surface and an outer surface extending upwardly from the bottom surface, wherein the bottom surface includes an incident surface and the outer surface includes emergent surfaces, wherein the outer surface includes at least one first surface unit that includes a light adjusting surface and an emergent surface, the light adjusting surface receives at least one part of light beams from the incident surface and adjusts the light beams to the emergent surface to emerge through the emergent surface, and emergent light beams are converged at focus.