Dear Recyclebank: I wear glasses and hard contact lenses. At a recent eye exam, the optician suggested disposable contact lenses. It occurred to me that I never before considered my nearsightedness to have an impact on the earth. What are the disposable lenses made of? Do they biodegrade? How about the packaging? Are glasses or laser correction surgery the greenest options? –E. M.

Dear E. M.: Disposable contact lenses have become increasingly popular since they hit the market in 1987. Back in 2003, the Contact Lens Institute estimated that over half of contact lens wearers were already wearing disposable lenses. However, while their convenience and hygiene seem to make them a natural choice, these lenses face the same sustainability challenges as most other “disposable” goods.

Disposable lenses are typically made of silicone-hydrogel, which, like most plastics, does not biodegrade, which makes then unsuitable for compost and harmful in the trash. Also, their very small size may make them nearly impossible for most recycling facility’s machinery to process. This typically means your lenses end up in landfills. The packaging your lenses come in is a factor in their relative sustainability as well. While outer cardboard boxes can be recycled, the blister packs that contain the lenses themselves pose more of an issue, as varying plastics are used and the foil seals are generally not recyclable. You may still be able to recycle the plastic portion if it’s a type of plastic your handler accepts.

Fortunately, the waste produced by disposable contact lenses isn’t extensive compared to other areas of personal care. A 2003 study pegged overall contact lens waste at just 0.5% of total personal waste. Plus, the same study determined that monthly disposables actually had LESS of a negative impact than conventional lenses due to the higher amount of waste associate with their two-step hydrogen-peroxide system. When it comes to your other options, old-fashioned glasses require an amount of raw material equal to about four years’ worth of daily disposable contacts, but don’t create the same amount of packaging waste and can be donated when you’re done with them. Additionally, laser correction surgery generates no additional waste and there are minor negative environmental impacts created by the lasers; however, the cost may be a deterrent.

If the health benefits and reduced risk of infection make the trade-off to disposable contacts worth it for you, know that the amount of annual waste you’ll be creating is relatively small, at three pounds or less. That said, if you choose to go disposable, choosing lenses that are meant to be replaced monthly or even weekly rather than daily will reduce the waste created by packaging and by the lenses themselves.

SOURCES: American Optometric Association, Contact Lens & Anterior Eye, Contact Lens Manufacturers Association, Contact Lens Update, Washington Post