A lens (10) for wide lateral-angle distribution of light from an LED light source (20) on a board and defining an axis (6). The lens includes a board-adjacent base (11) spaced from and around the axis, an inner light-receiving surface (30), an intermediate surface (40) and an outer output surface (50) configured for refracting light received from the inner and intermediate surfaces. The base forms an opening into a light-receiving cavity defined by the inner surface which includes (a) substantially planar front and back surface portions (31, 32) each extending from the opening and (b) an end surface portion (33) spanning the cavity between the front and back surfaces and comprising front and back segments (35, 36) extending inwardly from the front and back surface portions, respectively, and each angled with respect to the other. The intermediate surface is positioned and configured for reflecting light received from the inner surface toward the outer output surface.