Light emitting diodes (LEDs) have been around for nearly 100 years. The primary advantage of using LED lights is energy savings. It has become popular in the last couple of decades because its cost of manufacturing has come down, the unit cost of energy has risen, and the technology itself has improved. LED output can now be controlled automatically to suit the users’ needs.

Now that a cost-savings baseline has been established, more recent research has focused on improving light quality to improve the health and productivity of workers.

Recent research has helped us understand how light influences human behavior. Human circadian rhythm can be affected by different visible wavelengths, particularly in the blue-green region. Light coming into one’s eyes and stimulating the nervous system is a major influencer of the circadian system, which starts in the brain and regulates physiological rhythms throughout the body, affecting hormone levels and the sleep-wake cycle.
Certain neural receptors in the retina when they capture light of wavelength of about 490 nm which best causes the brain to stimulate other parts of the body (alertness). Furthermore, light with lower amounts of this wavelength range signals the body to settle down and prepare to rest.

Light can influence other activities, too, such as being energized during the day and falling asleep at night. Several university research laboratories and lamp manufacturers are trying to incorporate this into LED light technology. While LEDs can emit a very natural white color, part of its spectrum could contain a larger amount of rays in the blue-green region (470 nm to 520 nm wavelength), which can influence human circadian rhythm and behavior.

Finally, research is showing that the ideal wavelengths to show effects on human behavior also depends on the age of the subject, due to changes in the eye’s shape and cornea with aging. In general, as one ages, the wavelength needed to influence human behavior goes up. However, even as one may adjust the wavelength, the influence on behavior declines as one ages; again, the effects of aging on the physiological and hormonal properties.

Therefore, imagine an office where the lights are programmed to emit white light at all wavelengths, but especially around the 490 nm mark, the high point for alertness for young people, but also higher wavelengths for older workers. And then changing the mix of wavelengths to higher ones to get people to settle down at the end of the work day. That time may come sooner than we expect.

CCES has the experts to help you evaluate your lighting to optimize the energy savings, be more green, and improve your workers’ productivity. Contact us today at 914-584-6720 or at karell@CCESworld.com.