A lens includes a light incident surface and a light exiting surface. The light exiting surface includes a first curved surface, a first convex surface, a second convex surface, a second curved surface, and a third curved surface. The first curved surface is located at the center of the light exiting surface. The first and second convex surfaces are arranged at two opposite sides of the first curved surface respectively for converging the light exiting therefrom, the first convex surface, the first curved surface, and the second convex surface connect in sequence along a first direction. The first and third curved surface are arranged at another two opposite sides of the first curved surface respectively; the second curved surface, the first curved surface, and the third curved surface connect in sequence along a second direction substantially perpendicular to the first direction.