Contact lenses, worn by millions of people around the world, tend to shed microplastics when exposed to sunlight for a long time, according to a pilot study.

To determine the number of microplastics in the small samples, such as contact lenses, researchers from the universities of Nanjing and Hohai designed an automated system that took microscopic images of the samples, processed those images, and quantified any microplastics that were present.