A front sight assembly includes a self powered substantially permanent light source such as tritium source carried within a bore defined in a housing, where the housing preferably defines a structure symmetrically aligned along a central plane, where the bore carrying the light source has a central axis that lies within or parallel to the housing's central plane. The sight assembly housing terminates proximally in a proximal surface that faces the user when mounted on a firearm or other instrument. The sight assembly housing's proximal surface further includes a region surrounding or defining a periphery around the light source which is coated with, laminated with or altered to define a region of photo-luminescence that is substantially concentric with the center of the visible portion of light source.