Abstract: A substantially solid transparent body focuses light from an LED wholly immersed therein to a point external to the body. The body is composed of a substantially non-heat-conducting plastic material and has a surface with the curvature of a Cartesian Ovoid substantially in accordance with the formula L.sub.o .times.N.sub.o .times.L.sub.i .times.N.sub.i =C, whereL.sub.o is the distance from a point on the surface to the external point;L.sub.i is the distance from the LED to the point on the surface;N.sub.o is the index of refraction in air; andN.sub.i is the index of refraction of the plastic material.