A system comprising a first light source and a controller. The first light source is arranged to provide non-ocular photo-biological stimulation to a user via a first light emission. For example the first light source may take the form of an in-ear light source arranged to provide the photo-biological stimulation via at least one ear canal of the user. The controller is configured to coordinate control of the first light emission with a second light emission provided by at least one second light source providing ocular stimulation to the user. The second light source may take the form of one or more luminaires arranged to illuminate an environment of the user via ambient light. In embodiments, the controller may be configured to control the non-ocular light to counteract an effect on the user of the ambient light, or to enhance an effect of the ambient light.
