Natural night after sunset is associated with the absence or very low level of bioactive blue light content. At night, humans are not designed to safely see blue light. The lack of blue light provides a night signal to the master clock and triggers a chain reaction that activates hormonal and other pathways critical to maintaining health and avoiding depression, diabetes, obesity, cardiovascular disease, and breast cancer and prostate cancer.
Most energy efficient lights in the workplace today, including fluorescent and especially LEDs, which can emit blue-rich light, have a substantial downside health risk in operation, which is now recognized by the world Health Organization (WHO).
At night, the blue light content ideally should be as close to zero as possible.
New energy-efficient lights are becoming available,which provice good quality light whilst intelligently controlling the blue dosage according to the time of day and season to boost alertness and productivity and avoid exposure to the harmful effects of blue light at night
Exposure to the wrong light at night can lead to depression and mood disorders. Because of the high bio-active blue light wavelength content, these widely prevalent lights trigger newly discovered eye receptors and neural pathways to boost alertness and productivity during the day but at night cause a 35%-65% increase in the risk of obesity, diabetes, heart disease, sleep disorders and depression, as well as breast and prostate cancers.
Every evening, the hormone melatonin activates sleep and other nighttime processes in our bodies. Exposure to blue wavelengths of light during evening hours (or pre-sleep hours for shift workers) suppresses the release of melatonin and disrupts sleep (especially restorative sleep) and circadian rhythms.
Melatonin is a primary contributor to health. Research shows that light tells the body when to secrete and suppress melatonin. Too much light in the evening can advance the circadian clock, making it more difficult to fall asleep. Awareness of the impact of evening light is why leading device manufacturers have implemented night shift modes on phones and tablets.