The Environmental Costs of Contact Lenses
Updated: Apr 19, 2021
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Contact lenses, small plastic or silicone lenses that are placed directly on the eyes are a common alternative to glasses. These small prescription lenses can be used daily, weekly or monthly, and they can be hard and soft. However, unlike glasses, contact lenses wear down quickly and need to be disposed of. Therefore, while contact lenses are extremely convenient for many, there are hidden environmental costs that we do not normally consider.
A research study from the American Chemical Society found that 15 to 20 percent of contact lens wearers flush their lenses down the sink or toilet, which is the improper way to dispose of these single-use plastics. These improperly disposed contacts end up in wastewater treatment plants, resulting in 6-10 tons of plastic contact lenses in our waters a year. Contact lenses are clear, making them harder to analyze and detect at water treatment facilities, and they contain a different mix of plastic and silicones than most plastics, so wastewater treatment plants are not as well-equipped to detect them. These properties of contacts lead to the difficulties in detecting contact lens waste in treatment facilities.
So what happens when the contact lens waste reaches the oceans and lakes? Contacts are denser than water, so they sink to the bottom, generating countless obstacles to the aquatic wildlife that feed on the bottom of the oceans. As such, contact lenses degrade into microplastics, which aquatic animals mistake for food. They affect the digestive system of those animals, which in turn, affects the aquatic food chains. Eventually, some of these microplastics end up in our food, leading to human exposure to these plastic contaminants and pollutants.
Contact lenses are extremely helpful to the visually-impaired; some hard contact lenses help to reshape the cornea, and slow down the rate of myopia in younger people. The fact of the matter is that we can’t simply quit using them. However, we can restructure and reprogram the ways our wastewater treatment plants work, so that contact lens waste can be filtered out before it harms our wildlife, which is what Dr. Rolf Haden is trying to do with his research team, which looks into ways that we can restructure and reprogram wastewater treatments.
You can help make a difference as well! If you are a contact lens wearer, consider switching from dailies to biweekly or monthlies in order to reduce your waste output. Most importantly, be sure that you are disposing of contact lenses correctly, so that they don’t even have the potential to harm our environment.