Old contact lenses should never be flushed down the sink or toilet, and expired lenses shouldn’t go back in your eyes. The best options are recycling through a free program or tossing them in the trash as a last resort. What you do with the packaging matters too, since lenses themselves make up only a fraction of the total waste.
Why Flushing Is the Worst Option
Between 15 and 20 percent of contact lens wearers flush their used lenses down the sink or toilet. That adds up to roughly 1.8 to 3.36 billion lenses entering wastewater systems each year in the United States alone, contributing an estimated 20 to 23 metric tons of plastic to water treatment facilities annually.
Contact lenses don’t dissolve. Microbes in wastewater treatment plants weaken the plastic polymers, causing the lenses to fragment into microplastics rather than break down completely. These microplastics accumulate in sewage sludge (researchers found roughly one pair of lenses per two pounds of sludge) or pass through the treatment process entirely and enter rivers and lakes in reclaimed water. From there, they enter the food chain like any other microplastic pollution.
How to Recycle Used Lenses for Free
The Bausch + Lomb ONE by ONE Recycling Program, run in partnership with TerraCycle, accepts used contact lenses and blister packs from all brands, not just Bausch + Lomb. Participating eye care offices serve as drop-off locations, and you can find one near you by searching the locator map at terracycle.com/bauschrecycles.
To use the program, collect your used lenses and packaging, make sure everything is empty and dry, and bring it to an official drop-off location. The program accepts the lenses themselves, the plastic blister packs they come in, and the foil tops. These materials are too small and made from plastics that local curbside recycling facilities typically can’t process, so this specialized program is one of the only ways to keep them out of landfills.
What About the Rest of the Packaging?
Contact lens waste goes beyond the lenses. If you wear monthly or biweekly lenses, you likely have lens cases and bottles of multipurpose solution. The good news: lens cases (the base portion) and solution bottles are commonly made from HDPE plastic, which carries recycling code 2. That’s widely accepted in curbside recycling programs. Rinse them out and toss them in your recycling bin. One study found that reusable lens wearers can recycle about 78 percent of their total contact lens waste at home through standard curbside programs, once you separate out the lenses and blister packs.
The cardboard outer boxes that lenses ship in are recyclable through normal paper recycling. Break them down flat and include them with your regular recycling.
If Recycling Isn’t Available
If there’s no participating eye care office near you, the next best option is simply putting used lenses in the trash. It’s not ideal, but a lens sitting in a landfill causes far less environmental harm than one fragmenting into microplastics in waterways. Collect your used lenses in a small container and toss them with your regular garbage.
Don’t Wear Expired Lenses
If you found an old box of contacts and you’re wondering whether they’re still safe, check the expiration date on the packaging. Expired lenses carry real risks, and the problems go beyond mild discomfort.
The sterile solution inside sealed blister packs loses effectiveness over time. Bacteria, fungi, and other pathogens can grow in degraded solution, and putting that lens on your eye significantly raises the risk of infections like keratitis (an inflammation of the cornea) or conjunctivitis. Some of these infections can threaten your vision if left untreated.
The lens material itself also changes. Expired lenses become less permeable to oxygen, which can starve your cornea and lead to redness, pain, or corneal ulcers in severe cases. The polymers in the lens can break down chemically, potentially releasing irritating substances. The lens shape can warp slightly, creating a poor fit that rubs against your cornea and causes tiny abrasions. These scratches are painful on their own and also give infections an easy entry point.
Even if an expired lens feels okay at first, it will likely dry out faster than a fresh one. The materials that retain moisture degrade over time, leading to the gritty, dry sensation that comes with insufficient lubrication. Expired lenses can also develop cloudiness or surface deposits that reduce visual clarity, causing eye strain and headaches.
The simplest rule: if the expiration date has passed, recycle or discard the lenses and start with a fresh box.
Reducing Waste Going Forward
If the environmental footprint of contact lenses concerns you, a few choices can make a meaningful difference. Daily disposable lenses generate the most waste by volume, since you’re discarding a lens and blister pack every single day per eye. Monthly lenses produce fewer lenses for the trash, though you’ll go through solution bottles and cases instead. Either way, collecting everything and using a recycling program keeps the most material out of landfills and waterways.
Replace your lens case at least every three months for hygiene reasons, and recycle the old one curbside since it’s typically HDPE plastic. The same goes for empty solution bottles. Building a small collection bin near where you handle your lenses makes it easy to accumulate materials for your next trip to a recycling drop-off point.