Traditional Mexican Medicinal Plants for Ocular Diseases: Ethnomedicinal Evidence, Pharmacological Relevance, and Research Gaps from Unexplored Sources

Background/Objectives: Traditional medicinal knowledge remains underrepresented in pharmacological research because much of it is preserved in printed monographs, institutional collections, historical documents, and non-digitized ethnomedical repositories. This study aimed to document medicinal plants used in Mexican traditional medicine for ocular disorders and identify taxa of ethnomedicinal and pharmacological relevance. Methods: Three repositories were examined: the Medicinal Herbarium of the Mexican Institute of Social Security (IMSS), the open-access Biblioteca de la Medicina Tradicional Mexicana, and a pioneering undergraduate thesis addressing Mexican medicinal plants used for ophthalmological conditions. Data were manually extracted by two independent expert reviewers, with discrepancies resolved by consensus. Botanical nomenclature was updated using World Flora Online, and records were compared with previous Mexican ethnomedicinal information. Available pharmacological evidence was considered to contextualize the ethnomedical findings and identify taxa warranting further investigation. Results: The present contribution documented 232 ethnomedicinal records, corresponding to 174 species, 124 genera, and 57 botanical families. Asteraceae represented the predominant family, while Matricaria chamomilla was identified as the most frequently cited species. Notably, 165 ethnomedicinal records corresponding to 142 species identified in this work were absent from previous analysis of Mexican medicinal plants for ocular diseases, demonstrating the value of these repositories. Species such as Argemone ochroleuca exhibited notable ethnomedical relevance despite the limited pharmacological and clinical evidence currently available. Conclusions: The present work expands the existing ethnopharmacological knowledge of Mexican medicinal plants used for ocular diseases and highlights the value of integrating historical, institutional and digital sources into modern ethnopharmacological research. Furthermore, the findings identify and prioritize selected taxa for further pharmacological, toxicological, and formulations studies with potential ophthalmological applications.