An intelligent electronic device (IED) may be configured to detect arc flash events within a power system using stimulus measurements acquired by detection devices communicatively coupled to the power system. An arc flash event may be detected using a time-intensity comparison metric, such as an inverse time-over-stimulus metric, a cumulative stimulus metric, or the like. The stimulus may include electro-optical (EO) radiation produced in the vicinity of the power system, current measurements, or the like. The IED may detect an arc flash event if one or more of the stimulus types are indicative of an arc flash event. Responsive to detecting an arc flash event, the IED, or other protective element, may take one or more protective actions, such as issuing trip commands, or the like.