This paper was presented at the 14th Iranian Mining Engineering Conference. Safety and efficiency in tunnels and underground mines are highly dependent on the proper design of lighting systems. In this study, a specialized software application was developed in Python with a graphical user interface to simulate and optimize lighting conditions in the three primary tunnel zones: entrance, transition, and interior. The software employs the point-by-point calculation method and supports standard photometric data formats (IES and LDT) to evaluate key lighting parameters, including minimum illuminance, average illuminance, and uniformity. A binary search algorithm was implemented to determine the optimal spacing of luminaires, reducing energy consumption and the number of fixtures without compromising lighting quality. The outputs include illuminance distribution maps, central tunnel profiles, and comprehensive technical reports in PDF and CSV formats, enabling both technical and economic evaluation. A case study demonstrates that the proposed tool improves design accuracy and efficiency while enhancing safety, reducing operational costs, and supporting lighting layouts compliant with international standards.