Abstract: A visual display for indicating a level of ionizing radiation is mounted on a portion of an item of headwear, such as safety goggles, at a position within the peripheral field of vision of a wearer. Such a display advises a wearer of a level of radiation, including warning levels, in real time without requiring activity on the part of the wearer. In one embodiment, an ionizing radiation detector, accompanying circuitry, and the visual display are mounted on the glasses, such as on the frame. In another embodiment, a commercially-available detector is used to provide an output from a location remote from the headwear to actuate the visual display on the headwear. Various circuit embodiments are also disclosed.