Unlike conventional incandescent or fluorescent light sources, LEDs emit light at very specific wavelengths. Physiologists and psychologists have long understood how light can affect a person’s natural circadian rhythms. Consider, for example, the growing number of diagnoses of “seasonal affective disorder” that affects individuals in northern climates who have very limited sunlight disclosure during winter months. LED lights are now seen as a potential remedy for individuals whose circadian body clocks have been interrupted by environmental or other conditions.
Health and Lighting
Certain blue wavelengths of light are known to depress a body’s production of the melatonin hormone, which is produced to help a person relax and fall asleep. With less melatonin in his system, an individual will feel more alert and productive. Natural sunlight comprises a greater amount of blue wavelength light during the central part of each day, causing individuals to be more alert during bright daylight hours. When natural sunlight is insufficient, highly-tuned LED light at the targeted blue wavelengths can be an effective substitute.
Healthy Indoor Lighting
Likewise, warmer-coloured lighting can stimulate melatonin production and help a person fall asleep. These correlations can be used by a lighting designer to install and tune LED lighting systems in commercial, industrial, and residential environments. In a residential household, for example, LED lights can be configured to generate brighter blue-wave lighting during daylight hours, with transitions to warmer lighting in the evening. These lighting transitions can help to normalise a person’s circadian rhythms to allow the sound and restful sleep that is needed to recover from every day’s activities.
The Health Benefits of LED Lighting
Studies by international consulting organisations and health care providers have expanded on this use of LED lighting to form the broader concept of “human-centric lighting” or HCL. This concept is not unique or specific to LED lighting, but it does focus on the health benefits of exposing individuals to variable wavelengths of lighting during the day in order to modulate mood-altering melatonin levels. Because of their versatility and ability to generate specific and highly-tuned light wavelengths, LED lights are ideal for HCL applications. Health care professionals are looking in particular at using HCL theories to treat individuals who suffer from depression or anxiety disorders.
LED lighting engineers have also focused extensively on controlling and eliminating light flicker in LED products. Light flicker has been linked with headaches and other health problems that reduce productivity and a general sense of well-being.
As the uses and applications of LED lighting expand, individuals will also benefit indirectly from reduced carbon emissions from power generation facilities. LED lights generate the same or better illumination as incandescent bulbs with 50% less energy input. Lower power demands and reduced emissions will improve environmental air quality for everyone’s benefit. LED fixtures are also manufactured with no hazardous materials, and when they reach the ends of their useful lives, they can be discarded with no concerns over adding hazardous materials to landfills.