Microplastics and Nanoplastics in Eye Health: Ocular Exposure, Toxicity, and Clinical Implications

Abla Yousif Mohamed¹ , Asim AHMED ², Léa Fontaine ³

Abstract

Microplastics (MPs) and nanoplastics (NPs) are increasingly recognized as pervasive environmental contaminants with potential implications for human health, but their relevance to ocular tissues remains incompletely understood. This review synthesizes current evidence on ocular exposure pathways, detection of plastic particles in ophthalmic products and human ocular samples, and their potential toxic effects on the ocular surface and posterior segment. A structured literature search was conducted across PubMed, Scopus, Web of Science, and Google Scholar from database inception to 23 March 2026. Because of substantial heterogeneity in study design, particle characteristics, analytical methods, and reported outcomes, the findings were synthesized narratively rather than quantitatively. Available evidence suggests that ocular exposure may occur through airborne deposition, contaminated ophthalmic formulations, contact lens-related plastic debris, periocular cosmetic products, waterborne contact, surgical settings, and systemic translocation after inhalation or ingestion. MPs have been detected in tear fluid, meibum, pterygium tissue, cataract surgery-related samples, commercial eye drops, vitreous samples, and post-mortem human retinal tissue. Experimental studies indicate that these particles may induce oxidative stress, inflammation, mitochondrial dysfunction, epithelial injury, goblet cell loss, tear film instability, lacrimal and meibomian gland dysfunction, retinal pigment epithelial damage, microvascular impairment, and increased vascular permeability. However, current human evidence is limited, largely observational, and subject to major methodological challenges, particularly contamination during sampling and variability in particle detection and identification techniques. Although the available literature supports biological plausibility for ocular toxicity, definitive causal relationships, real-world exposure thresholds, and the clinical significance of ocular plastic burden remain uncertain. Further standardized, longitudinal, and mechanistic studies are needed to determine the true impact of MPs and NPs on eye health.