Batman's cowl has also been depicted with shifting optical lenses that identify suspect's identities, as well as their weak points (through medical records), while simultaneously avoiding the possibility of eye identification. The cowl's lenses incorporate multiple vision modes like infrared vision (heat sensors), night vision, and ultraviolet vision, and a digital camera for obtaining evidences. Also, in "The Dark Knight", Batman uses a sonar concept (via Cellphone) introduced by Lucius Fox. This technology is utilized by using echolocation to triangulate objects via cell phones. In "Detective Comics" #838 (January 2008), it is revealed that Batman also has an echolocation system in the cowl. In ', Batman wears a special motorcycle helmet when riding his Batcycle that is molded with bat ears to accommodate his cowl's ears. In "", Batman extensively uses a sophisticated "detective mode" vision enhancement built into the cowl that allows him to see enemies in darkness, including through walls, see their condition and state of alertness, and detect and identify hidden objects and analyze evidence. It also gives him the white eyes while it is activated.