In this Review the use of light to address stimuli-responsive molecular and supramolecular systems with applications in information processing and binary logic is discussed. Molecular photoswitches are at the focal point of the herein summarized works. Light offers great advantages in terms of spatiotemporal control and remote triggering. As an additional surplus, excited state processes, such as energy- and electron-transfer can be precisely designed such that photoswitchable systems yield the desired logic operation or function. As opposed to chemical signals, photons are traceless reagents, enabling the recycled operation and reconfiguration of the discussed devices. The herein in an account-style summarized examples provide an overview of merging photoswitching with information processing, hopefully serving as a starting point for further research in this exciting field.