From the initial production of plastics in 1950 to the year 2015, 8.3 billion metric tons of plastic were generated worldwide.¹ Because of the short useful lifespan of plastic, 6.3 billion metric tons of this plastic has become waste; 9% of it has been recycled, 12% has been incinerated, and the remaining 79% is in landfills or has been released directly into the natural environment.^1,2 At the current rate of plastic production and waste management, there will be approximately 12 billion metric tons of plastic waste by 2050.¹

Most commonly used plastics are not biodegradable, and hence, the materials accumulate rather than decompose. Those that do degrade take hundreds of years to break down. Plastics in the environment are weakened by sunlight, which causes them to break into smaller fragments.³ Similarly, plastics discarded in wastewater treatment plants also do not decompose with typical microbial treatment. These plastics become structurally weakened and then fragment into smaller pieces and into microplastics within the wastewater sludge. This sludge enters the environment as fertilizer or is shipped to landfills. With rain, the microplastics in the waste water leach out to the marine and freshwater environments.

As of 2010, it was estimated that 4.8 to 12.7 million tons of plastic waste had entered the marine environment.³ This plastic waste is ingested by sea birds, fish, and other organisms including invertebrates. More than 250 marine species (including crustaceans, fish, sea turtles, sea birds, seals, manatees, and whales) have been documented eating plastics,⁴ which, in turn, find their way into the human food chain. Contact with plastic increases the risk for coral to become diseased from 4% to 89%.⁵ Among a study of 175 autopsied dead penguins, 14.86% had ingested debris of which plastic accounted for 57.69%; one penguin had a perforated stomach from a straw, which probably caused its death.⁶ Debris in the stomach of whales has caused occlusion of the intestinal tract, gastric rupture, and starvation following gastric blockage.⁷ Plastic waste affects all levels of marine life. Additionally, while there is still no known link between plastic ingestion by ocean animals and human health, there is growing concern in this regard, and this is an active area of research.⁸

WHAT ABOUT CONTACT LENS WASTE?

Currently, there are more than 45 million contact lens wearers in the United States.⁹ As of 2018, 35% to 46% of all patients wear daily disposable contact lenses.¹⁰ Each contact lens weighs 30 micrograms, and the use of contact lens products by end consumers comprises 0.5% of the total environmental waste.¹¹

Rolsky found that among more than 400 contact lens wearers surveyed, 19% discard their contact lenses into the toilet or sink. On an annual basis, this results in an estimated 2.5 billion contact lenses weighing approximately 44,000 pounds entering the wastewater treatment plants in the United States. A pair of contact lenses was found for each two pounds of waste sludge.¹² When exposed to microbes such as those found in biological wastewater treatment plants, the bonds holding together the contact lenses break, causing the contact lenses to fragment into smaller pieces and to ultimately form microplastics.¹³

As the contact lens market shifts more toward daily disposable contact lenses, society may become concerned with the plastic waste. Contrary to intuition, however, the ecological waste of one-day disposable contact lenses is not that different from that of reusable contact lenses plus contact lens solution. Whereas an annual supply (365 pairs) of one-day disposable contact lenses, including the cartons, blister packs, and foil, produces 1kg of waste per year, reusable contact lenses plus contact lens solution for the year would produce 0.87kg of waste.¹⁴ This doesn’t include the shipping boxes and the carbon footprint of shipping materials needed to get the contact lens solution boxes from the distributors to the retail stores.¹⁵

With regard to the plastic waste of contact lens solution cases, one multipurpose solution contact lens case and one peroxide system contact lens case are equivalent to four and eight years’ worth of daily disposable lenses, respectively. The average plastic waste of one multipurpose solution or hydrogen peroxide solution bottle is equivalent to more than 2.5 years of daily disposable lenses.¹⁶

WHAT IS BEING DONE?

Fortunately, all of the waste related to contact lenses is now recyclable. Much material science research is currently being conducted to better recycle the current waste plastics as well as to create more biodegradable plastics.

The current recycling process is both time intensive and costly because the materials need to be pre-sorted. The recycled plastics are often of low-quality polymers, which cannot be used for many current materials. Newer advances are leaning toward chemical recycling materials, which require less energy and can combine mixed plastic wastes to avoid the need for sorting.¹⁷ Other researchers are studying the use of a fungus, Pestalotiopsis microspora, to degrade polyurethane in both aerobic and anaerobic environments like those found in waste landfills.¹⁸ In addition, transportation fuels made from post-consumer recycled plastic waste that is directly mined from landfills are being developed.¹⁹

Biodegradable plastics development is also a growing industry. For example, new biodegradable plastic polymers are being made of fructose-like, light-sensitive molecules; after three hours of ultraviolet light (350nm) exposure, the light-absorbing molecules break the long chain of the plastic molecules, resulting in a liquid solution that can be used to make more plastic.²⁰ Other researchers are using itaconic acid derived from a fungus, Aspergillus, to make carpets, paints, plastics and coatings, and synthetic rubber, among other things; itaconic acid can also be used as a hardening agent in organosiloxanes for use in contact lenses.²¹ In 2018, Lego started making certain elements, such as trees, leaves, and bushes, from a plastic produced using sustainably sourced sugarcane; the company hopes to use sustainable materials in all core products and packaging by 2030.²²

SUSTAINABILITY EFFORTS FROM MAJOR SOFT LENS MANUFACTURERS

As many forward-thinking companies have started to become environmentally conscious, contact lens companies also have worked to establish environmentally friendlier efforts. Following is a summary of these efforts from the largest manufacturers of soft contact lenses. This summary is meant to provide examples of such contact lens company initiatives and may not be all inclusive.

Alcon Alcon has policies in place to recycle and minimize waste to reduce its environmental footprint. In 2017, the company decreased water consumption by 8% by using only recycled water in its chiller, hence saving 14.1 million gallons of water each year as well as a 2% reduction in energy usage. Alcon prevented 4,900 tons of non-recycled hazardous waste by recycling and prevention, and the company recycled 79% of all operational waste. In addition, package design and sizing have been minimized and simplified to use less material, hence reducing landfill and biohazard waste. The company reported using 10% renewable electricity and 14% recycled water in its operations, and 98% of solvents used in the company’s operations are recycled offsite.²³

In addition, Alcon’s Health, Safety and Environment policy states that the company uses natural resources responsibly and minimizes the environmental impact of its activities and products over their life cycle.²⁴

Bausch + Lomb Bausch + Lomb, in collaboration with TerraCycle, initiated the One by One Recycling Program in the United States. It enables used contact lenses and packaging to be recycled properly, separating out the plastic from the foil tops. As of April 2018, 2.5 million used contact lenses and contact lens packaging have been recycled, diverting 14,000 pounds of waste from landfills and the natural environment.²⁵ Bausch + Lomb has also implemented the use of biodegradable lens shipping packaging, recyclable molded paper fiber packaging, and a more recyclable clear polyethylene terephthalate packaging for its Renu solutions. Additionally, the company has promoted the use of renewable energy in its production plants and makes every effort to purchase environmentally sustainable products.²⁶

CooperVision CooperVision received multiple awards at the 2017 Environmental Health and Safety Summit for its manufacturing plant in Costa Rica. The energy-efficient plant recycles up to 95% of its solid waste, including materials used in production such as cardboard, wood, paper, and oil. Ninety percent of the facility’s electricity is derived from renewable sources such as solar, wind, geothermal, and hydro energy. In addition, all of its New York State operations are powered by 100% wind-based electricity, and CooperVision’s Mountpark, UK site is powered by 100% biomass. The company changed its contact lens mold closure technology to use certain raw materials in their entirety without waste. Cardboard containers are reused five to 10 times before they are recycled in the company’s Puerto Rico and Hungary facilities. Ninety-nine percent of plastics used in manufacturing are repurposed into producing traffic cones and molded chairs. The company also recycles its water in plant cooling towers and uses collected rainwater for its lavatories and climate cooling systems.²⁷

Johnson & Johnson Vision Care Johnson & Johnson Vision Care has partnered with TerraCycle to recycle contact lenses in the United Kingdom. The company also received the 2017 Environmental Leader award for Acuvue Oasys 1-Day by using sustainable packaging and reducing its packaging by putting more contact lenses into a larger box. The new packaging saved 57 tons of paper for the United States in 2017, and the reduced weight resulted in 13% less energy required during shipping and distribution. The company also improved its manufacturing processes for Acuvue Oasys with HydraLuxe to result in a 12% reduction of energy use.²⁸ The blister packaging for Acuvue Oasys was also redesigned so that opposing blisters nest next to each other, hence reducing polypropylene usage and paper packaging.²⁹ Johnson & Johnson has also recently become a chartered member of the New Plastics Economy Global Commitment.³⁰

Menicon Menicon has been innovative with its environmentally friendly Miru 1Day Menicon flat packs. The flat packs are 1mm thick, so they have 80% less packaging bulk and less saline compared to conventional blister packs. In addition, Miru 1Day Menicon Flat Packs use a “foil on foil” design as opposed to standard blister packs that consist of foil over polypropylene plastic. Plus, the entire flat pack is recyclable.³¹ Within its manufacturing plants, Menicon is active in conserving water and electricity by innovating energy consumption and streamlining operations. Beyond contact lenses, Menicon is also planting seedlings for forest restoration³² and recycling coffee grounds from Starbucks stores in Tokyo to be converted into feed for dairy cows.³³

Which Plastics Are Recyclable?

Have you ever wondered what all of the numbers mean within the chasing-arrows triangle on plastic containers? The numbers identify the type of plastic used. The seven different numbers found within the chasing-arrows triangle allow for better plastic material separation at recycling centers because not all plastics are biodegradable and recyclable.

# TYPE OF PLASTIC	MATERIAL USES	WHAT CAN IT BE RECYCLED INTO?
PETE or PET (Polyethylene terephthalate)	Some contact lens solution bottles, soft drink bottles, water bottles, mouthwash containers, peanut butter jars, sports drink and cooking oil bottles, oven-safe food trays	New containers, straps, paneling, carpet, polar fleece, tote bags
HDPE (High-density polyethylene)	Some contact lens solution bottles, juice bottles, milk jugs, butter/margarine tubs, grocery bags, bleach/detergent bottles, shampoo bottles, washing and shower soap bottles, trash bags	Laundry detergent bottles, drainage pipes, pens, oil bottles, picnic tables, doghouses, benches, floor tiles
PVC (Polyvinyl chloride)	Flooring, shower curtains, clear food packaging, window frames, children’s toys	Mats, speed bumps, mud flaps, decks, cables
LDPE (Low-density polyethylene)	Six-pack rings, shopping bags, highly resistant sacks, squeeze bottles, frozen food bags, bread bags	Floor tile, paneling, shipping envelopes, trash can liners, compost bins
PP (Polypropylene)	Contact lenses blister packaging, contact lens cases, medicine bottles, straws, ketchup bottles, bottle caps, packing tape, furniture, luggage, toys, bumpers	Bins, rakes, bicycle racks, ice scrapers, brushes, brooms, signal lights
PS (Polystyrene)	Disposable plates, disposable cutlery, toys, cafeteria trays, meat trays, cosmetic bags, costume jewelry, CD cases, take out containers, egg cartons	Rulers, egg cartons, light switch plates
OTHER (Other plastics)	Safety glasses, polycarbonate, acrylic, nylon, fiberglass, iPod cases, five-gallon water bottles, combination of different plastics	Plastic lumber, custom-made products

WHAT CAN PRACTITIONERS DO?

The drinking straw industry has initiated a national ban campaign on plastic straws and cutlery, moving to paper, metal, and recyclable materials. Similarly, efforts to decrease the use of single-use shopping bags has been implemented in 11 U.S. states.³⁴ Contact lens companies are doing their part to help reduce contact lens waste by making all contact lens packaging recyclable.

But much more can be done. As eyecare providers, we can also contribute to this recycling movement. Our lens-wearing patients can be better educated on not discarding their lenses in toilets and sinks and on the importance of recycling their contact lenses, lens packaging, lens solution bottles, and lens cases. By working together, we can contribute to a healthier planet. CLS

REFERENCES

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