The billions of contact lenses being disposed of by flushing them down drains and toilets is exacerbating the plastics pollution problem that is threatening the health of the environment as well as the human food chain. Contact lenses can survive the filtering processes of water treatment systems, says Fulton Schools Professor Rolf Halden, director of the ASU Center for Environmental Health Engineering. That means old contact lenses end up adding to the increasing accumulations of toxic pollutants on land and in the ocean, where they are ingested by land animals and sea creatures — including those that are sources of food for people.