Three reasons your patients should not be flushing their contact lenses down the toilet
One year’s worth of daily disposable contact lens wear creates about 1 kg of waste,1,2 but did you know that the lenses themselves only make up about 10 grams (or 0.1%) of the total waste?2 Surveys have found about 1 in 5 contact lens wearers in the UK3 and USA4 flush their lenses down the toilet or sink, and that is the last thing patients should be doing with their used lenses. In fact, an estimated 44,000 kg of contact lens waste is released into water systems every year as a result of flushing lenses down the toilet or sink.4 That’s equivalent to 98 polar bears!5
Here are 3 reasons our contact lens patients shouldn’t be flushing their contact lenses down the toilet or sink.
1. It puts plastics where they don’t belong.
When flushed down the toilet or sink, contact lenses can end up in wastewater systems or directly in our oceans.4 Inappropriate disposal of contact lenses can have devasting consequences. Large and small fragments of contact lenses have been recovered from sewage sludge.4 This is worrisome, as 50% of treated sewage sludge in the US is used as fertilizer in farming, which means potentially more plastics could be introduced into the food chain.6
2. The problem with microplastics.
With time, all plastic products, including contact lenses, break up into small fragments (microplastics) making them difficult to detect and remove from the environment.7,8
3. Health concerns in water and on land.
Fragments of plastic smaller than 5mm are classed as microplastics.9,10 Studies have shown that microplastics are consumed by a wide range of marine life7,11 and it’s unclear the full extent this can have on their mortality, morbidity, and reproduction.12 This is an additional potential route for microplastics to enter our food chain, and the full impact of microplastics on human health is not yet fully known.13 There’s never been a more critical time to reflect and reduce our impact on these vulnerable aquatic ecosystems and the wider environment.
How should I advise my patients when it comes to throwing away their contact lenses?
Your patients have two options when it comes to discarding away their used lenses.
The best option is to save them up and drop them off in a specialist recycling bin. One provider is TerraCycle, who have partnered with Bausch + Lomb in Canada and USA to offer a free recycling service for all brands of contact lenses and blister packs (plastic trays and foils). All patients have to do is collect their used contact lenses, blister trays, and foils in a bag, and drop them off at a collection point. Patients can find where their nearest collection bins are located on the TerraCycle website. As a practice, you can also sign up to be a public drop-off point. Simply register with TerraCycle (Canada, USA) to get started.
If patients can’t find a drop-off location close to them, they can purchase a Zero Waste Box from TerraCycle, where a range of non-hazardous flexible or rigid plastic products can be recycled by them. When the box is full of collected materials, the patient ships the box off to TerraCycle who will take care of the sorting and recycling.
If neither of those options is accessible for your patient, the final option would be to simply throw them in the bin. Remind your patients they should never flush contact lenses down the toilet or the sink.
Summary
Whether you have a patient brand new to contact lenses or one that’s been wearing them for decades, you’ll now know why it’s so important to remind them to never flush their contact lenses down the toilet or sink. These recycling services are fairly new and evolving, so expect to keep up to date with the latest developments in this field.
Share this infographic (pdf / image) with your patients and on your social media platforms, tagging @COREEyeNews and #CLSustainability #SustainableEyecare.
See our other pages to learn how much (or little) waste is generated from wearing contact lenses and how your patients should sort and dispose of their contact lens waste.
References & Resources
1. Routhier J, Freitas MD, Hickson-Curran S. Daily disposable versus reusable contact lenses: a close match when it comes to the impact on the environment. Cont Lens Anterior Eye 2012;35:e2.
2. 2. Smith SL, Orsborn GN, Sulley A, et al. An investigation into disposal and recycling options for daily disposable and monthly replacement soft contact lens modalities. Cont Lens Anterior Eye 2022;45(2):101435.
3. Johnson & Johnson Vision. Johnson & Johnson Vision expands contact lens recycling programme as survey reveals majority of wearers are unaware of recycling options. Published June 26, 2022. Accessed April 16, 2025.
4. Rolsky C, Kelkar VP, Halden RU. Nationwide Mass Inventory and Degradation Assessment of Plastic Contact Lenses in US Wastewater. Environ Sci Technol 2020;54(19):12102–8
5. Dies Und Das. Convert weight into animals. Accessed August 1, 2024.
6. Cha J, Cupples AM. Detection of the antimicrobials triclocarban and triclosan in agricultural soils following land application of municipal biosolids. Water Res 2009;43(9):2522–30.
7. Marcharla E, Vinayagam S, Gnanasekaran L, et al. Microplastics in marine ecosystems: A comprehensive review of biological and ecological implications and its mitigation approach using nanotechnology for the sustainable environment. Environmental Research 2024;256:119181.
8. Lofty J, Muhawenimana V, Wilson CAME, et al. Microplastics removal from a primary settler tank in a wastewater treatment plant and estimations of contamination onto European agricultural land via sewage sludge recycling. Environmental Pollution 2022;304:119198.
9. United States National Oceanic and Atmospheric Administration. Microplastics. Accessed April 16, 2025.
10. European Chemicals Agency. Microplastics. Accessed April 16, 2025.
11. Nelms SE, Barnett J, Brownlow A, et al. Microplastics in marine mammals stranded around the British coast: ubiquitous but transitory? Sci Rep 2019;9(1):1075.
12. Cole M, Lindeque P, Halsband C, et al. Microplastics as contaminants in the marine environment: a review. Mar Pollut Bull 2011;62(12):2588–97.
13. Li Y, Tao L, Wang Q, et al. Potential Health Impact of Microplastics: A Review of Environmental Distribution, Human Exposure, and Toxic Effects. Environ Health 2023;1(4):249–57.