Spectre's Eye

The Spectre's Eye is a curio added by Meet Your Fight worn in the Head slot (Charm slot before 1.3.0). When equipped, it periodically applies the Glowing effect to hostile monsters in a 40x40x40 cube centered on the wearer, making them visible through walls. The effect can take a few seconds to apply to monsters entering the range, and persists for a few seconds after they exit it or the curio is unequipped.