Understanding visual absorption from first principles

At the molecular level, the process of vision is regulated by the visual opsins pigments. All the opsins have the same global structure and contain the same photosensitive molecule, the retinal chromophore, and it is only the difference in protein environment that tunes their absorption over a wide range of wavelengths. In this thesis, we investigate Rhodopsin, the opsin responsible for dim-light vision, from a theoretical point of view and focus on how to obtain an accurate description of its absorption properties from first principles. To achieve this goal, we employ a multiscale approach and a hierarchy of theoretical techniques.