<p>This review explores mesoporous silica nanoparticles (MSNs) as emerging nano-drug delivery systems for ocular diseases and provides a comprehensive overview of their application in ophthalmic drug delivery, including eye anatomy, ocular barriers, MSNs structural characteristics, synthesis approaches, surface functionalization strategies, drug-loading mechanisms, as well as recent advances in patents and clinical trials. Among all the senses, vision plays a crucial role in everyday life. Ocular disease causes visual impairment and significantly reduces the quality of life, resulting in expensive medical care. Currently used treatments mostly utilize traditional formulations, which are limited by the physiological and anatomical barriers of the eye. Nanotechnologies, particularly MSNs, have emerged as a promising approach to overcome these limitations by enhancing drug loading, targeted drug delivery, and sustained release. An extensive literature review on the synthesis, functionalization, toxicity, safety, and applications of MSNs was conducted using multiple databases, including relevant patents and research studies. The reviewed articles demonstrated that MSNs exhibited improved drug penetration, improved mucoadhesion which extends longer precorneal residence duration, clinical efficacy and acceptable safety profile. Several recent research papers and patents further support the potential of MSNs in treating several ocular disorders effectively. According to the extensive literature survey, MSN-based nanodrug delivery systems provide significant advantages over conventional ocular formulations by overcoming ocular obstacles and enhancing therapeutic effect. Further standardized and clinical research is needed to validate their safety, long-term stability, and clinical effectiveness. Overall, MSNs represent a promising platform with significant potential for ophthalmic drug delivery.</p> Graphical Abstract <p></p>