A glasses lens can curve inward–called concave – to fix near-sightedness. Or the lens can curve outward – called convex – to fix far-sightedness. You can tell what kind of lenses you have ...

Save guides, add subjects and pick up where you left off with your BBC account. The questions in this quiz are suitable for GCSE physics students studying convex and concave lenses, real and ...

By carefully placing nanostructures on a flat surface, researchers have significantly improved the performance of so-called optical metasurfaces in conductive plastics. This is a major step for ...