An investigation into disposal and recycling options for daily disposable and monthly replacement soft contact lens modalities

Abstract

Purpose

To examine the annualised waste and end-of-life disposal options with two representative soft contact lens (CL) modalities.

Methods

The component parts of two representative soft CL modalities were catalogued, separated, weighed and inspected for material identification: somofilcon A soft CLs (clariti elite, CooperVision Inc.) used with multi-purpose solution (MPS) (All in one Light, CooperVision Inc.) and somofilcon A CLs (clariti 1 day, CooperVision Inc). Using a model that assumed compliant wear and care of CLs, the mass of material solid waste generated by CL use over a year was calculated. Disposal options were explored using household and specialist recycling streams in order to develop recommendations for responsible disposal of CL waste.

Results

Full-time daily disposable (DD) CL wear generates 1.06 kg of waste annually compared to 0.83 kg generated by reusable-monthly replacement daily wear (‘reusable’) CLs. Plastic was the dominant material in both modalities. With full-time use of DD CLs, 64% of waste by mass was plastic blister trays. For full-time use of reusable CLs, where figures from lens and MPS packaging are combined, plastics accounted for 67% of waste by mass. MPS bottles alone made up almost half the waste (45%) associated with full-time reusable CL wear.

Conclusion

Full-time DD wear generates 27% more waste annually than full-time reusable lens wear. Reusable CL wearers can recycle 78% of waste at home. DD lens wearers have access to recycling options that allow them to recycle 100% of CL related waste. Full-time CL lens wear represents just 0.20–0.26% of the 412 kg of household waste generated per person, per year in the United Kingdom. Worn CLs should never be disposed of down the sink or lavatory. CL wearers should be aware of responsible end-of-life recycling and disposal options for all CL waste.

Introduction

The increased awareness of environmental sustainability and reliance on disposable plastics raise some important questions for eye care professionals (ECPs) with regard to the environmentally responsible options for the disposal of soft contact lenses (CLs) and associated packaging. This issue is perhaps most pertinent to single-use, daily disposable (DD) soft contact lenses which were introduced in the mid 1990s, and which have transformed the contact lens market worldwide, providing a relatively safe [1] and convenient form of contact lens wear to millions worldwide [2].

Across all industries, it is estimated that 8300 million tons of virgin plastics have been produced to date. It is suggested that 60% (4900 million tons) have been discarded and are accumulating in landfill or the natural environment. If current production and waste management trends continue, roughly 12,000 million metric tons of plastic waste will be in landfills or in the natural environment by 2050 [3].

The 2017 British Broadcasting Corporation documentary Blue Planet II brought the effects of plastic pollution on the marine environment to a wider public audience. Single use and disposable plastic items such as plastic bags, straws and cutlery were identified as a substantial source of plastic marine pollution [4].

Focus fell on CL wearers when a 2018 conference report and subsequent paper [5] reported that 21% of CL wearers in the United States (US) were flushing their lenses down the sink or lavatory. They estimated that in the US alone this amounted to about 20–23 tonnes of waste water-borne plastics annually and the work made headlines around the world [6], [7], [8]. Against this backdrop, anecdotal reports to ECPs indicated that some CL wearers were beginning to question the relative benefits of the convenience of DD lenses against the perceived environmental impact of increased waste.

The CL industry had already taken steps toward end-of-life options for contact lenses. In 2016 the first recycling program for contact lenses and their packaging was launched in the United States [9]. Similar schemes launched in selected European markets, including the United Kingdom (UK) in 2019 [10], [11]. Through a network of locations, many of which are situated within optometry practices, individuals can drop-off contact lenses and blister packaging into a designated recycling box.

Promoting recycling has become a key priority in the UK and the European Union (EU). The EU intends to increase the amount of packaging waste that is recovered and recycled. Among the targets to be achieved by 2030 are a recycling rate of 85% for paper and 55% for plastic [12]. The UK government has an ambition of zero avoidable waste by 2050 and eliminating avoidable plastic waste, where practicable, at each stage of the product life cycle by 2042 [13].

Despite public engagement and new legislative targets on waste, only one paper has been published in the literature on the subject of CL waste [14]. This 2003 study illustrated the environmental impact of waste generated through CL use but there was no investigation in that paper as to end-of-life disposal.

This new study takes some of the original methodology from the work of Morgan et al [14] and proceeds to investigate disposal options. The aim was to quantify the amount of waste generated by a year of full-time and part-time soft CL wear, to identify the type of waste generated and to report on responsible disposal. The results of this study should be relevant to ECPs, consumers and the wider CL industry.