A sighting device is used to aim along a line of sight at a target. The sighting device includes a reticle structure formed of a roof prism assembly having an inclined final roof-prism mirror surface that is not perpendicular to the line of sight. The inclined final roof-prism mirror surface is the last...http://www.google.com/patents/US7386953?utm_source=gb-gplus-sharePatent US7386953 - Sighting device with multifunction illuminated reticle structure
