Why you should not flush your contact lens down the toilet or sink

Thursday, 11 August 2022 by Vision Direct

This will have happened to each of us contact lens wearers at least once in our life: You're in the bathroom removing your contact lenses, and you don't have a bin nearby. The temptation to flush your discarded lenses is strong, and throwing contact lenses in the sink or toilet would seem the easiest and fastest solution, but it is one of the most damaging behaviours towards our environment. We share how best to dispose of your lenses correctly.

How many people wear contact lenses?

Do you know how many people use contact lenses? According to recent research, there are about 4.2 million Britons, 45 million Americans, and 140 million people worldwide who wear them. What if all of these people threw their lenses down the sink or toilet? It would have an incredibly damaging impact on our environment.

We all agree: contact lenses are an extraordinary invention, and a revolutionary tool for those with vision problems. For those of us who use them, wearing or removing contact lenses is a key routine of everyday life. Likewise, the appropriate disposal of contact lenses should also be a part of our routine.

2 contact lenses

What are contact lenses made of?

First, let's start by clarifying the composition of contact lenses. Currently, contact lenses are classified according to the different materials used for their construction. There are 3 main types: rigid lenses, RGP lenses (or rigid gas permeable) and soft contact lenses. Soft lenses are the most commonly used and are made of hydrogel (or silicone hydrogel, which has become increasingly popular in recent years), a soft, flexible and above all, highly breathable and permeable plastic substance. The hydrogel absorbs water very easily, so it is extremely difficult for the lenses of this material to be separated from the liquids of the drains when they are filtered.

What happens when you throw your contact lenses in the sink or toilet?

Once lenses enter the drain, they end up in the sewers and arrive at the water treatment plants. Here they pass through filters that separate the larger residues and discard non-biological elements from the flow. Most contact lenses are too small and flexible to be isolated in this process, and therefore continue their journey in the water ready to be treated. The treatment involves the presence of bacteria that destroy biological waste, but it is unable to completely dissolve the contact lenses, merely reducing them into fragments. As a result, these particles end up in the sea and can be ingested by fish and other marine animals. Thicker lenses, such as monthly contact lenses, are even able to reach the sea intact and deposit on the seabed along with other waste, altering the already precarious balance of our marine ecosystem.

Person holding sieve containing microplastics found on the beach

Microplastics danger

There is a lot of talk about plastic bottles, straws, or cotton buds. But for some years now it has been realised that contact lenses also contribute to the microplastic pollution that is spreading in our waterways. They may seem infinitesimal in size compared to the vastness of our seas and oceans, but the number of contact lenses that wearers throw away every day is truly enormous, and therefore must be considered as a waste in all respects. Research from Arizona State University estimates that between 15-20% of contact lens wearers have a bad habit of throwing them down the sink or toilet.

What about biodegradable contact lenses?

Contact lenses have come a long way since their invention in the 1800s. Contactology is constantly evolving and is always looking for new materials for the production of more eco-sustainable lenses. Furthermore, surveys show that most contact lens wearers would be happy to recycle them, but many don't know how. Despite the efforts of recent years, biodegradable contact lenses don’t exist yet, so each of us must do our part! So where do you throw your contact lenses? We at Vision Direct take the health of the environment very seriously, and in our own small way, we always try to provide you with all the information you need to recycle contact lenses correctly. We will never stop repeating it: recycling is important, and disposing of contact lenses in the right way can make a difference!

Practical tips to avoid throwing your contact lenses down the sink or toilet

Whether you use monthly lenses, two weekly lenses or daily lenses, it doesn't matter. Throwing contact lenses down the sink or toilet is wrong. Here are some tips from our team that might come in handy:

Contact lens on a finger over the sink
  • When at home, if possible, always keep a bin in the bathroom or nearby.
  • When you’re away from home, for example with friends or in a public place where there is no bin, try to keep the used lenses in a handkerchief and then throw them in the unsorted bin as soon as possible.
  • If you are often away from home, take an old lens case with you to store your used contact lenses and then dispose of them as soon as possible. It is so small that it can easily be carried in your purse, backpack or pocket!
  • If you continue to find the correct disposal of contact lenses hard, perhaps it's time to try fortnightly or monthly lenses. They will need to be disposed of in the same way, but less frequently than with disposable contact lenses.
  • Share this simple information with as many friends and relatives as possible. They may not be aware of how harmful it is to throw contact lenses down the sink and toilet. Or they might even give you other helpful tips on how to recycle your lenses!

Where to throw away your contact lenses?

Let's not just focus on the lens itself, but also consider everything that is part of the package. Recycling contact lenses is important, and as you will see, it only takes a few simple steps to respect the environment.

  • Contact lenses: recycling contact lenses is very simple, because they are thrown into the unsorted.
  • Contact lens blister: The lens blister consists of a plastic part and an aluminium tab. Then, separate these two components and throw them into the plastic and aluminium respectively.
  • Maintenance liquid: the liquid contained inside the blister can be safely poured into the sink.
  • Paper packaging: the packaging of your lenses, together with the Vision Direct packaging containing your order, is thrown into the paper and cardboard bin.
  • Lens holder and empty bottle of contact lens solution: Both are made of plastic, so they must be thrown into the appropriate container.

Remember, these are just general guidelines. Each city or municipality may have different rules for the separation of waste, so it is always best to check the area where you live.

Diagram showing what parts of a Vision Direct delivery can be recycled

Vision Direct’s recycling service

Want to make things easier for yourself? Did you know that we offer a free recycling service to our UK customers? If you’re based in the UK, just pop your lenses, blister packs, and used cases back into the packaging we sent your order in, print off a royal mail label, and send your used eye care products back to us for recycling!

Let’s summarise

Do you still have doubts about where to throw your contact lenses? Here is a summary to help you make the right choices and safeguard our planet!

  • Contact lenses are not biodegradable. For this reason, lenses should be disposed of carefully.
  • Contact lenses break down into particles that are not filtered and therefore end up in our seas, increasing water pollution.
  • Contact lenses should never be thrown into the household waste, but thrown into the unsorted.
  • Choosing to replace contact lenses with glasses does not mean making a greener choice. All it takes is a little more attention.
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