Dietary and Formulation Potential of Natural Oils and Fats in Ocular Health and Disease: Mechanisms, Evidence, and Future Directions

Natural oils and fats are multicomponent lipid matrices composed predominantly of triacylglycerols with source-specific fatty-acid profiles, together with variable amounts of phospholipids and minor lipophilic constituents. This narrative review discusses the nutritional, biological, and pharmaceutical relevance of oils from plant, terrestrial animal, and marine sources in ocular health and disease. Whole natural oils and fats are distinguished from isolated oil-associated constituents, multi-ingredient formulations, pharmaceutical oil phases or excipients, and engineered lipid-delivery systems. The discussion focuses on fatty acids, phospholipids, carotenoids, tocopherols, phytosterols, phenolic compounds, and other lipophilic constituents in relation to tear-film stability, epithelial homeostasis, inflammatory regulation, retinal function, and ophthalmic delivery. The available literature encompasses human studies, experimental models, cell-based research, and formulation studies. Human research is concentrated mainly on ocular-surface outcomes and product-specific interventions, whereas the literature concerning most intraocular and retinal conditions is derived predominantly from preclinical or mechanistic studies. The review also considers the influence of oil source, composition, extraction, refining, cooking, oxidation, formulation characteristics, administration route, and safety on the interpretation of oil-related ocular research.