We need to have a talk with 6 million to 9 million Americans. It turns out that about that many people are likely flushing their contact lenses down sinks and toilets, and they need to stop.
It may seem like a convenient way to get rid of your daily lens, but they could actually be washing into waterways and ending up in the ocean.
Contacts are made of plastic, which we definitely don't need any more of in the sea.
According to USA Today, researchers from Arizona State University conducted a comprehensive contacts disposal study and found out some pretty disheartening information.
The study found that 15 to 20 percent of American contact lens-wearers are dumping them down sinks and toilets instead of trash cans, according to science news site Eureka Alert. Since an estimated 45 million people wear contacts, and many wear daily contacts, that's a huge amount going down the drain.
Each year, 6 to 10 metric tons of these lenses are ending up in wastewater.
The problem with flushing lenses stems from their inability to be properly processed by sewage water treatment facilities. According to the New York Times, study co-author Rolf Halden said that contact lenses, designed to be flexible for your eyes, can therefore fold up during water treatment and easily pass through filters.
They also, like most plastics, don't break down. "These are medical devices — you would not expect them to be super-biodegradable," Halden pointed out to the NYT.
Per USA Today, the study found that lenses just broke down into smaller pieces of plastic, which are harder to filter out and easily end up slipping through the full treatment system.
These types of microplastics can litter our seas in huge amounts.
As we saw with microbeads in personal care products, microplastics can change sand composition and make turtle nest sites too hot, per The Conversation. They can also be easily ingested by animals along the food chain, adding to toxicity levels in seafood consumed by other sea creatures and humans. According to NatGeo, a French study also found that oysters that ate microplastics had their reproduction levels cut in half.
Those are just some of the dangers microplastics pose. So it's especially concerning that contact-lens plastic could be adding to an already huge plastic-pollution problem in the ocean.
Although USA Today noted that the study wasn't able to determine how much plastic from lenses ends up in waterways or the sea, it seems clear that a portion does.
According to CNN, sewage sludge is a byproduct of sewage treatment plants, and it's used in many fertilizers. And we know that there are lens particles present in sewage sludge because the study found that there are two lenses in every 2 pounds of it, per USA Today. Then that sludge is used on land and can be washed into waterways via rainfall or artificial watering systems, per CNN.
So lens plastic is almost certainly entering our water systems and probably leading out into the sea.
Unfortunately, it's also not as simple as just throwing the lenses away in the garbage instead of down the toilet.
We know that trash ends up in the sea too, at alarming rates, with 8 tons of plastic alone being dumped into the sea each year, per NatGeo.
But there is one surefire way to make sure your lenses aren't hurting the sea.
USA Today reported that eye product company Bausch + Lomb has a recycling program especially designed for contact lenses. They partnered with TerraCycle, a company that focuses on small-item recycling.
To participate, USA Today says you should take your used lenses and packaging to an approved doctor's office (find one near you here), or mail them to an approved recycling center. (Print a shipping label here.)