Optogenetics, an innovative approach integrating photonics and genetic engineering, enables precise control over molecular and cellular processes, opening up exciting new opportunities for precision-guided medicine. In this review, we highlight recent advances in optogenetic tools and their applications across a range of medical conditions, including vision restoration in retinitis pigmentosa via light-activated ion channels, precise immune response modulation in cancer immunotherapy, and blood glucose management in diabetes through controllable drug release. Optogenetics also plays a critical role in bioelectronic medicine, enabling seamless communication between electronic systems and biological tissues to enhance therapeutic precision. Finally, we discuss the challenges and potential transition of optogenetics from experimental models to clinical therapies, emphasizing its immense potential to transform future medical treatments.