An LED module includes an LED having an optic axis and a lens fixed over the LED for refracting light emitted by the LED. The lens has a same cross section along a front-to-rear direction thereof. The lens has an inner incidence surface facing the LED and an outer emission surface. The inner incidence surface is concave toward the emission surface. The emission surface has a middle part around the optic axis of the LED concave toward the incidence surface, and two convex lateral parts off the optic axis of the LED. A peak intensity for the light generated by the LED and penetrating through the lens occurs within the convex lateral parts of the emission surface.