Researchers in the US have been investigating the final journeys taken by disposable contact lenses. They found 15-20% of US users simply flick these fiddly lenses down the drain via the bathroom sink or toilet. The Arizona State University study suggests that much of the plastic material then ends up in waste water treatment plants. The lenses are consequently spread on farmland as sewage sludge, increasing plastic pollution in the environment. Around 45m people wear contacts in the US, while rates in other countries

In recent years, the concept of extended producer responsibility (EPR) has caught on, first in Europe in the 1990s and since then in the rest of the world, including the U.S. The concept is relatively simple: Companies that make consumer goods are given responsibility for managing their products and packaging at their end of life. The concept, as the Journal of Cleaner Production points out, is to turn what was formerly waste “into the ‘food’ for industry and the next