Ocular diseases pose a significant threat to vision and even lead to irreversible blindness, severely impacting patients' quality of life. Traditional ocular therapies often fall short of providing effective treatment due to the unique anatomical structure of the eye, particularly in the penetration of eye barriers. Recent advancements in nanotechnology have demonstrated significant potential for addressing these limitations. Nanocarrier-based drug delivery systems offer unique advantages such as sustained drug release, enhanced bioavailability, and specific tissue targeting, which can effectively pass through barriers and act on the lesion site. In this review, we systematically examine the common routes for nano-ocular drug administration and highlight the advantages of nanomedicines in ocular drug delivery. We provide a comprehensive analysis of various nanomaterial platforms, including nanoparticles, nanomicelles, nanosuspensions, nano/microemulsions, nanowafers, and hydrogels. While acknowledging the remarkable potential of nanodrugs in controlled release, barrier penetration, and formulation diversity, we emphasize the need for further research into long-term biocompatibility and clinical validation of novel nanotherapeutic agents.