LED illumination is controlled light from light-emitting diodes used to reveal reflective surfaces, optical signatures, or other small visual cues that are hard to see in ambient light. In security work, the goal is not to brighten a room, but to change how a target surface responds so software or an operator can detect it more reliably.
This matters in cyber security because many threats have a physical component: hidden cameras, tampered devices, and other covert sensors often rely on lenses, glass, or shiny internals that interact with light in distinctive ways. By sweeping LED light across an area, defenders can expose reflections or glints that indicate a concealed lens. Attackers can also use similar illumination and imaging techniques during reconnaissance to inspect hardware or identify weak points. LED illumination is therefore a practical sensing method for both inspection and detection, but it works best as part of a broader verification workflow, not as a standalone proof.