Handheld spectrometers that use metalenses (lenses made of a metamaterial surface rather than ground and polished glass) have been created by Federico Capasso’s group at Harvard University’s John A. Paulson School of Engineering and Applied Sciences (SEAS; Cambridge, MA). The handheld spectrometers are capable of the same performance as large benchtop instruments, and are potentially useful for health-care diagnostics to environmental and food monitoring.