Researchers develop a novel design approach to achieve nonlinear photochromism using easy-to-synthesize rhodamine spirolactam derivatives Nonlinear photochromic compounds that utilize low-energy light have received significant attention. They result in enhanced contrast and spatial resolution in photochromic reactions and allow multiple photofunctions in single molecules. However, they require complex molecular design, which limits their wide applicability. Now, researchers have achieved nonlinear photochromism using low-energy light in an easily synthesized perylene-substituted rhodamine spirolactam derivative, offering a novel design approach for simpler photofunctional materials.