How much are your plastic contact lenses polluting the planet?

18 November 2021

Author: Kate Green

plastic contact lens pollution

How many contact lenses are thrown away?


Most of us are actively trying to reduce our impact on the environment, whether that’s recycling our plastic bottles or taking public transport instead of driving. However, something we might not consider is the effect of our disposable contact lenses on the environment. As much as we may try to avoid single-use plastics where possible, contacts are actually a huge part of the problem. While the contact lenses themselves are made of plastic, we also need to consider the packaging they come in – usually made of yet more plastic with a foil layer on top – and the fact that many contact lens wearers use them and dispose of them on a daily basis.


Disposable contact lenses first became available in 1987 and within the next 15 years, more than 50% of contact lens wearers were relying on disposable lenses for daily use. 14 billion contact lenses are thrown away each year in the US (both in the bin and down the sink or toilet), and 21% of these end up in the water system. This means that there are over 2.5 billion lenses entering American sewage every year. In the UK, almost 4 million people wear contact lenses, but 77% of them say they would be keen to recycle their lenses if they could, or knew how to. There are some contact lens recycling schemes available but they are clearly not known about widely enough, or easy enough to access, in order to encourage people to use them.


What are the different types of contact lenses?


There are several different types of contact lenses, each with their own level of environmental impact. A big part of the lens’s environmental impact is how often it is disposed of. Most contact lens wearers rely on daily disposable contact lenses which undoubtedly contributes to the plastic problem caused by lenses being thrown away. However, there’s great convenience that comes with daily lenses, one of the main ones being not having to bother with contact lens solution and storage in order to keep your lenses clean for their next use. You can also try extended wear contacts which you can keep in overnight for several days, while continuous wear contacts can be worn 24 hours a day for up to 30 days. These lenses clearly have a smaller impact on the environment as you would be discarding 12 sets of lenses a year, rather than a potential 365 pairs annually with daily disposables.


Aside from the frequency with which you throw away your lenses, there is also the matter of what they are made from. All About Vision provide a very useful summary of the different types of contact lenses and their respective materials. However, despite the differences in the exact lens material, it’s still important to note that they are all made from types of plastic.

  • Silicone hydrogel lenses are the most commonly-used type of contact lenses. They are made from a soft lens material through which more oxygen can pass, benefiting the health of your eye.
  • Soft lenses are very thin and flexible, providing a comfortable contact lens experience. They are also made from hydrogels which are plastics that contain water in order to hydrate the eye.
  • Gas permeable lenses are rigid lenses which typically are used by people with astigmatism, as they maintain their shape in the eye. They also allow oxygen through to the eye but aren’t always as comfortable as softer lenses.
  • Hybrid contact lenses are hard in the middle and have an outer ring of a softer hydrogel material. This combines the benefits of gas permeable lenses with the comfort of hydrogel lenses.


The material from which contact lenses are made is particularly worrying when it comes to environmental concerns, as the type of plastic is specially developed to be water absorbent. This means that once the contact lenses enter the sewer system, they are especially effective at picking up other toxins that happen to be in the water system, for example pesticides and herbicides. This helps the toxins travel further and spreads them up various food chains, as well as into parts of the environment or areas where they usually wouldn’t be used. Researchers at the University of New York suggest that the impact of contact lenses is actually worse than other microplastics, due to their absorbent qualities.


What are the environmental impacts of contact lens waste?


As contact lenses are made of plastic, it’s clear that over time they will start deteriorating and breaking down into tiny microplastics. A microplastic is defined as a piece of plastic which is 5mm or smaller, which isn’t actually much larger than the size of a contact lens anyway. When a contact lens is flicked down the sink or flushed down the toilet, it enters the sewer system. Research was carried out by a team from Arizona State University who looked into how contact lenses contribute to pollution in our soil and waterways. The team specifically analysed how quickly the lenses broke down in wastewater treatment tanks and found that it took 172 hours for them to deteriorate. This is more than enough time for them to travel to other parts of the water system, including those which are designated for use on farmland. The effects on wildlife and animals in the area can be severe, both with whole contacts lenses as well as when they break down into microplastics.


Further to this, microplastics from sources such as lenses are also regularly consumed by animals which either come across the plastics when they’re in soil or crops, or when they drink the affected water supply. It is at this point that the microplastics enter the foodchain, even working their way up to humans. In fact, microplastics have been detected in humans and even in newborn babies. Even if the contact lens itself deteriorates to a point where it’s no longer visible in water, that doesn’t mean there are no smaller particles still floating around, naked to the eye.


If you’re looking to reduce your environmental impact, consider switching from daily disposables to monthly contact lenses, or rely on your glasses more. You could even think about having laser eye surgery, which could be the best way to give you freedom from glasses and contact lenses, while reducing your contribution to water pollution. Please give us a call on 0800 093 1110, request a free information pack, or book your free consultation online if you would like to find out more about laser eye surgery.

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