An optical lens includes an optical transparent body which has an upper surface, a lower surface, a lateral surface and a lower concave portion. The upper surface includes a central upper concave portion, an outwardly-concave curved surface continuous from the central upper concave portion, and an inwardly-concave curved surface continuous from the outwardly-concave curved surface. The lateral surface is connected between the inwardly-concave curved surface and the lower surface. The lower concave portion is recessed from the lower surface.