From flushing contact lenses (CL) down the toilet, to debates over what can or cannot be recycled, the past five years have seen considerable global media coverage on the potential detrimental effects that CL wear can have on our environment, especially with the continued growth of daily disposable (DD) lenses.1
Many consumers are aware of how their habits can negatively affect the environment and make concerted efforts to make positive change to lessen their impact on the planet.
Some lifestyle modifications are easy to achieve but in CL wear, where challenges such as prescription ranges and availability, ocular health needs and a patient’s budget intersect, it can be difficult for patients to feel that CL wear is a green option.
How much waste do my CLs generate?
The amount of waste a CL wearer generates is small, relative to the amount of domestic waste in our daily lives. Smith et al2 found 1.062kg of waste is generated from DD use across one year if worn full-time (360 days per year).
In comparison, full-time wear of monthly replacement CLs generates 0.835kg of waste, after taking into account the use of multipurpose lens care solutions and lens cases.2 Thus, full-time DD lens wear results in roughly 20% more waste than monthly lenses. Patients who wear DD lenses three to four days a week generate similar amounts of waste to those on a monthly replacement modality.2
These findings are very similar to Routhier et al,3 who also calculated how these amounts of waste compare to daily use of other common single-use items and products (figure 1). Their findings show the waste generated from CL use, regardless of modality, is small relative to other lifestyle habits, such as drinking bottled water daily. This supports calculations that CL waste makes up only approximately 0.22-0.54% of typical household waste generated per person in the UK.
Figure 1: Annual waste generated from daily (365 days) consumption or use of common everyday products. Data from Routhier et al.3 Drinking one bottle of water per day generates 10 times more waste than using reusable or daily disposable contact lenses every day
Are DDs worse than monthlies for the environment?
To answer this question, we need to consider each individual CL component encountered by a CL wearer (figure 2). While a patient on a reusable lens modality will use fewer CLs (and therefore generate less waste related to foils and blister trays), the necessity for CL solutions generates additional waste each month, assuming they are a compliant patient. The bottles from multipurpose solutions make up 45% of the total annual waste from full-time reusable lens wear.2 Furthermore, if liquid waste is taken into consideration, total annual waste (wet and dry) in reusable lens wear is more than double that generated from DD wear.2
On the topic of CL care products, there are additional factors in the product lifecycle and supply chain that also need to be considered. The production of care products involves additional freight and transportation of raw materials (including chemicals), energy and water consumption during the manufacturing process, in addition to the carbon footprint related to subsequent distribution.
The next consideration is how the different waste components listed in Figure 2 can be managed after use. From DDs, 100% of waste can be recycled, either through household waste (cardboard) or by TerraCycle, a specialist recycling scheme that accepts CLs, foils and blister trays, which are difficult or costly to recycle in typical household recycling schemes.2 In comparison, 19% of waste generated from reusable lens wear, all arising from the CL care system, is destined for landfill and cannot be recycled.2
Figure 2: Components of each element of contact lens products. Adapted from Smith et al, 2022.2 Colour-codes indicate the potential for the component to be recycled, where: green=can be recycled by typical household recycling systems or specialist recycling systems, orange=may be recycled using a specialist recycling scheme outside of the common scheme, and red=cannot currently be recycled
Is it true that I harm aquatic life by using contact lenses?
CLs can become a source of macro- and micro-plastic pollution when discarded incorrectly. CL wearers should not flush lenses down the toilet or the sink.
A survey of CL wearers in the UK found 27% flushed their CLs down the toilet or the sink.5 This is similar to findings in the US where 21% of survey respondents behaved similarly, releasing an equivalent of 44,000kg of CL waste annually into wastewater systems.6
These inappropriate disposal methods can have devasting consequences. Large and small fragments of CLs have been recovered from sewage sludge6 and since 50% of treated sewage sludge in the US is used as biosolids (processed organic matter from sewage used as fertiliser) in agriculture,7 this can potentially introduce more plastics into the food chain.
Furthermore, micro-plastics have been found to be consumed by a wide range of marine life and it is unclear the effects this may have on factors, including mortality, morbidity and reproduction.8
However, the discovery of micro-plastics in the digestive tracts of all deceased marine mammals found along the British coast9 is raising great concerns about human impacts on vulnerable aquatic ecosystems. Appropriate disposal of all elements of CL wear is vital to prevent further environmental harm.
What about the manufacturers?
Major CL manufacturers have made impactful changes to their processes by adopting environmentally sustainable practices.
In basic waste management principles, preventing waste is the preferred option with reuse, recycling, recovery and disposal being options further down the waste hierarchy.10
Most major CL manufacturers have demonstrated an ongoing commitment to sustainable practices by implementing these principles throughout the product lifecycle.
Alcon,11 Bausch + Lomb,12 CooperVision,13 Johnson & Johnson Vision14 and Menicon15 have all made changes in operational and manufacturing processes. These include: reducing energy and/or water use, increasing use of electricity from renewable sources, minimising product packaging, changing shipping practices to lower carbon options and diverting waste from landfill.
Alcon,11 Bausch + Lomb,12 CooperVision13 and Johnson & Johnson Vision14 have attained awards or certifications from various independent organisations for their demonstrated efforts in sustainable practices.
Alcon16 and CooperVision17 have partnered with Plastic Bank, a social enterprise that establishes ethical plastic collection and recycling programmes in coastal communities globally,18 to offer net plastic neutral CLs for several products in each of those manufacturer’s portfolios.
For every box of CLs sold that are a part of this initiative, an equivalent number of credits are purchased by the company to fund the collection, processing and reuse of general plastic waste that is equal to the weight of plastic in the CL products and packaging.
To date, CooperVision has recovered the equivalent of 114.8 million plastic bottles from the oceans since this partnership19 and, due to its success, expanded the range of products in this initiative to include MiSight 1 Day and the Biofinity family of CLs.20
Johnson & Johnson Vision21 and Bausch + Lomb12 have partnered with international specialist recycling company, TerraCycle, to provide free contact lens recycling programmes in the UK and North America, respectively.
Both companies provide practices with a recycling bin that accepts CL waste, collected and brought in by patients. Once this bin is full, the practice uses a pre-paid shipping label to send the container to TerraCycle, who processes the collected materials and recycles them into post-consumer products, such as furniture or gardening equipment.22,23
As patient awareness continues to grow, eye care professionals (ECPs) will be challenged to take a step back to reflect on how they can continue to care for our patients without detriment to the environment.
Continuous, small incremental changes by CL manufacturers, ECPs and patients can lessen our environmental footprints to create a brighter future for all.
- Alison Ng is an optometrist and lead clinical scientist at the Centre for Ocular Research & Education (Core) and Lyndon Jones is the director at Core.
References
- Morgan P, Woods C, Tranoudis IG, et al. International Contact Lens Prescribing in 2022. Contact Lens Spectrum. 2023;38:28-35.
- 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;45:101435.
- Routhier J, De Freitas M, Hickson-Curran S. Daily Disposable Versus Reusable Contact Lenses: A Close Match When It Comes to the Impact on the Environment. Contact Lens and Anterior Eye. 2012;35:e2.
- Morgan SL, Morgan PB, Efron N. Environmental Impact of Three Replacement Modalities of Soft Contact Lens Wear. Cont Lens Anterior Eye. 2003;26:43-6.
- Optical Express. 97% of Contact Lens Users Are Damaging the Environment. https://www.opticalexpress.co.uk/magazine/article/97-of-contact-lens-users-are-damaging-the-environment. Accessed: 12 February 2023.
- Rolsky C, Kelkar VP, Halden RU. Nationwide Mass Inventory and Degradation Assessment of Plastic Contact Lenses in US Wastewater. Environmental Science & Technology. 2020;54:12102-8.
- Cha J, Cupples AM. Detection of the Antimicrobials Triclocarban and Triclosan in Agricultural Soils Following Land Application of Municipal Biosolids. Water Research. 2009;43:2522-30.
- Cole M, Lindeque P, Halsband C, et al. Microplastics as Contaminants in the Marine Environment: A Review. Mar Pollut Bull. 2011;62:2588-97.
- Nelms SE, Barnett J, Brownlow A, et al. Microplastics in Marine Mammals Stranded around the British Coast: Ubiquitous but Transitory? Scientific Reports. 2019;9:1075.
- European Commission. Waste Framework Directive. https://environment.ec.europa.eu/topics/waste-and-recycling/waste-framework-directive_en. Accessed: 12 Feburary 2023.
- Alcon. Alcon 2021 Corporate Responsibility Report. https://www.alcon.com/sites/g/files/rbvwei496/files/2022-09/2022-Alcon-Report-0901_v2_WEB.pdf. Accessed: 13 February 2023.
- Bausch Health. Environmental, Social and Governance Report - Fall 2021. https://www.bauschhealth.com/siteassets/PDF/BauschHealthCSRReport2021.pdf. Accessed: 13 February 2023.
- CooperVision. Coopervision Sustainability Report Card. https://coopervision.com/sites/coopervision.com/files/coopervision_sustainability_report_card_june_2019.pdf. Accessed: 13 February 2023.
- Johnson & Johnson Vision. Johnson & Johnson Vision for Good Impact Review 2021. https://www.jjvision.com/jjvision_impact_report_2021.
- Menicon. Menicon Integrated Report. https://www.menicon.com/img/ir/Menicon_Integrated_Report_2021.pdf. Accessed: 13 February 2023.
- Bank P. Plastic Bank’s Partnership with Alcon. https://plasticbank.com/client/alcon/. Accessed: 15 Feburary 2023.
- Bank P. Plastic Bank’s Partnership with Coopervision. https://plasticbank.com/client/coopervision/. Accessed: 15 February 2023.
- Bank P. If You Could Stop Plastic from Entering the Oceans, Would You? https://plasticbank.com/about/. Accessed: 15 February 2023.
- CooperVision. Plastic Neutrality Dashboard. https://plastic-neutral.coopervision.com/plastic-neutrality. Accessed: 15 February 2023.
- CooperVision. Coopervision Expands Plastic Neutrality Initiative to Include Biofinity® and Misight® 1 Day in the U.S. https://coopervision.com/our-company/news-center/press-release/coopervision-expands-plastic-neutrality-initiative. Accessed: 15 February 2023.
- Johnson & Johnson Vision. Johnson & Johnson Vision Expands Contact Lens Recycling Programme as Survey Reveals Majority of Wearers Are Unaware of Recycling Options. https://www.jjvision.com/press-release/johnson-johnson-vision-expands-contact-lens-recycling-programme-survey-reveals. Accessed: 13 February 2023.
- TerraCycle. Bausch + Lomb Every Contact Counts Free Recycling Program. https://www.terracycle.com/en-CA/brigades/bausch-and-lomb-en-ca. Accessed: 13 February 2023.
- TerraCycle. The Acuvue® Contact Lens Recycling Programme. https://www.terracycle.com/en-GB/brigades/acuvue. Accessed: 13 February 2023.