A light detecting device, particularly one which indicates illumination by a laser, and methods for its use. The device includes at least two light detectors which each comprise a light sensor and a light control filter. The light control filter includes microlouvers arranged so that the microlouvers of the two different light detectors are at different angles. The light detecting device may be used to determine the direction to the source of the light detected. Further, two or more devices may be combined into a system that allows for a user to determine the distance to the source of light, particularly laser light emitted by a laser rangefinder. The system is designed to be functional under combat or other battlefield conditions and relatively simple and inexpensive to manufacture.