Worldwide, humans produce about 2 billion tons of garbage a year, most of it ending up in stinky, potentially dangerous landfills. Anything we can do to reuse and recycle our castoffs helps the planet.

Swipe through to learn about 7 things you might not have known you can recycle.

When your vision prescription changes, there’s no reason to toss your old glasses in the trash. Many optometrists and stores such as Target and Walmart collect old eyeglasses. They'll check the prescription and send them to people in need in developing countries.

The St. Jude’s Ranch for Children accepts the fronts of used greeting cards, which they repurpose when teaching teens life and work skills. They can’t accept cards from Hallmark, American Greetings or Disney, however, due to copyright issues. Send your cards to St. Jude’s Ranch for Children, 100 St. Jude’s St., Boulder City, NV 89005.

You probably know the big box office supplies stores will take your used ink cartridges, but did you know they also recycle pens? Just drop off used-up pens and they'll take care of the rest.

There’s even a program that accepts used toothbrushes in order to recycle them. Check with your dentist’s office to see if they participate.

Plastic cards such as hotel keys, gift cards and credit cards can be melted down and reused. Be sure to chop up credit cards before putting them in the recycling bin.

An outfit called HolidayLEDs accepts broken Christmas lights. In fact, if you send them your old broken string lights, they’ll recycle them and send you a coupon to put toward new lights, as well.

Photography: Amazon

Many Nike stores accept worn out sneakers through their Reuse-a-Shoe program; check with your local store to see if it participates. The company either reuses shoe parts or donates the shoes.