The front opening of a lamp body with a bulb disposed therein is covered with a lens. The lens is segmented into a plural number of segmental areas. A first fisheye step group composed of convex fisheye steps and a second fisheye step groups composed of concave fisheye steps are alternatingly formed in the segmental areas. In the first fisheye step group, real images of the light source are formed on the front side of the lens by the convex fisheye steps. In the second fisheye step groups, virtual images are formed on the rear side of the lens by the concave fisheye steps. The distance between the real and virtual images of the light source creates an appearance of depth for the lamp.