A new study has found that all tested commercial lubricant eyedrops contained microplastic contamination, raising questions about product safety and packaging standards in ophthalmic care.
Published in Eye (2025), the pilot study by researchers from Singapore and Australia provides the most detailed quantification to date of microplastic contamination in over-the-counter tear-replacement solutions packaged in single-use plastic vials.
Using both light microscopy and advanced Laser Direct Infrared (LDIR) chemical imaging, the research team analysed six widely used brands of non-prescription eyedrops. Every product tested contained microplastics, with the number of detected particles ranging from as few as 15 to more than 18,000 per millilitre of solution.
Nine types of polymers were identified – including polyethylene, polypropylene, polystyrene, polyvinylchloride, polyethylene terephthalate, polycarbonate, polymethylmethacrylate, polyamide and polyurethane.
The study’s authors say the findings highlight an under-recognised source of ocular exposure to microplastics, particularly among patients using eyedrops long-term for conditions such as dry eye disease or glaucoma.
“This investigation illuminates a clinical paradox: the very therapeutics prescribed to treat ocular ailments may expose an already compromised ocular surface to a significant burden of microplastic contaminants,” the authors wrote.
Packaging and production among likely sources
The researchers suggest that the microplastic particles likely originate from multiple points along the product lifecycle. Degradation of plastic vials during production, transportation and storage may be a key contributor, but contamination could also arise from raw ingredients or manufacturing equipment.
Even mechanical actions such as twisting open a vial cap may release particles, the authors note. Variability in microplastic counts between samples and production batches further supports the likelihood of multiple contamination sources.
While polyethylene fragments appeared most closely linked to the vial material itself, the presence of other polymers such as polyamide and polyurethane suggests broader systemic contamination within the supply chain.
Implications for patient safety and regulation
Microplastic exposure has been associated in prior research with ocular inflammation and elevated intraocular pressure, as well as broader systemic health risks. Though this study did not assess clinical outcomes, its findings raise concerns about the cumulative impact of chronic microplastic exposure on the eye’s surface.
The authors call for urgent, coordinated action between scientists, manufacturers and regulators to identify and minimise sources of contamination.
They recommend the development of low-shedding packaging materials and industry-wide standards for microplastic testing in ophthalmic therapeutics.
“To ensure patient safety and product integrity, implementation of stringent, industry-wide regulations and standardised testing protocols for microplastics in all ophthalmic therapeutics is recommended,” the paper concludes.
The next research frontier
The study acknowledges several limitations, including its small sample size and the detection threshold of the LDIR system, which cannot quantify particles smaller than 20 micrometres. Nonetheless, the authors describe their results as a crucial first step in understanding how microplastics may enter ocular therapeutics – and the potential implications for eye health.
Future research, they say, must determine the biological effects of these contaminants, trace their sources more precisely, and assess the full extent of ocular and systemic exposure.
Reference:
Jaeger J, Burke M, Wu D, Curren EE-M, Leong SCYL, Symons R, Lim BXH, Su X, Mehta JS, Riau AK, Lim CHL. Microplastics identified in commercial over-the-counter lubricant eyedrops. Eye (2025).
