A new study has found that contact lenses can shed microplastics when exposed to sunlight for long periods of time. Researchers from the universities of Nanjing and Hohai used an automated system to quantify the number of microplastics in six different types of contact lenses from various brands and of different lifespans. The lenses were stored in water and exposed to simulated sunlight for the equivalent of 30 or 90 days, with water samples analysed after each exposure. The study found that lenses exposed to sunlight over time can shed tiny fragments of plastic, though the health impact is unclear. The researchers estimate that more than 90,000 microplastic particles per year could be shed from some lenses if worn for 10 hours a day. Further studies are needed to determine the impact of direct exposure of microplastics to eyes.