Physical and chemical characterisation of ophthalmic lens-grinding wastewater: uncovering environmental implications

in both anatase and rutile crystalline forms in the lens coatings, both of which are recognised as emerging environmental pollutants. The characteristic N-H stretching vibrations of polyurethanes were detected in the FTIR analysis. Other hazardous contaminants, including particles below 2 µm, heavy metals, bisphenol A, phthalates, and fluorine-containing compounds, were also identified through SEM, NMR, and GC-MS. The presence of these substances raises significant concerns, as they are known endocrine-disrupting chemicals and persistent organic pollutants, which pose a significant risk to aquatic ecosystems and human health. Our findings revealed that while global lens consumption is driven by diverse regional preferences and multiple factors, waste generation is inherently systemic and independent of consumer choice, representing a structural technological constraint of current optical manufacturing processes. This study provides new, valuable information to alert the practitioners, competent authorities, policy makers, and society, supporting the development of future policies, alternative materials, and improved waste management strategies within the downstream ophthalmic value chain.