Artificial light has been used as a treatment for depression since the 1980s. The indications have since broadened from seasonal depression to non-seasonal depression including bipolar, geriatric, and chronic depression. Light acts through retinohypothalamic connections from specialised retinal neurons to central nuclei involved in circadian and emotional regulation. This review illuminates the current strategies directed towards utilising natural daylight or electric lighting mimicking the dynamic spectrum and intensity of daylight to improve treatment in modern hospital settings.