The visual, biological and emotional benefits of light

Several research projects have sought to document the effects of artificial lighting in a range of colour temperatures and intensity levels on elderly careresidents. Improved sleep quality and sleep patterns, a reduction in depressive symptoms and an increased sense of wellbeing are some of the effects that have been seen in residents with dementia. 

Light has a significant impact on wellbeing and performance. Our daily circadian rhythms are controlled by several ‘zeitgebers’ (a rhythmically occurring natural phenomenon that acts as a cue in terms of regulation), of which light is the most important external factor.1After the discovery of a third type of photo-receptor on the retina of the eye - the ganglion cells2- we now understand more about how light regulates hormone balance. These ganglion cells contain melanopsin, a protein that is sensitive to blue light in particular.1

During blue light exposure, signals are sent to an internal clock, which is a collection of cells inside the brain. These cells then regulate the release or suppression of the sleep hormone melatonin.3The same light has an effect on cortisol4and serotonin levels.5