Why? Because sunlight is good for us, physically and mentally. It’s the natural form of light, and we function best in a natural environment.
Unfortunately, most of us can’t enjoy that environment as often as we should. The demands of a daily schedule, career, home, and family put us under artificial light for most of our waking hours.
Conventional man-made illumination is less than ideal for many reasons. For one, it emits energy in an unbalanced or incomplete portion of the light spectrum. Ordinary incandescent and fluorescent light bulbs can’t produce the broad, consistent range of wavelengths that the sun provides.
Energy from the sun comprises visible light in a range of wavelengths. An incandescent bulb is deficient in producing the shorter, blue light waves. Sunlight illumination offers a more balanced and constant range of visible light across the spectrum. It also augments the amount of available blue light. Some evidence suggests that the application of balanced full-spectrum light can promote a healthy, normal sleep/wake cycle. Research supports the hypothesis that exposure to this light in the early evening can help older adults sleep better at night.
Other studies indicate that full-spectrum illumination may help in improving sleep and learning ability in adolescents. Scientists at the Rensselaer Polytechnic Institute Lighting Research Center report that teenagers deprived of morning full spectrum light are getting less sleep and possibly scoring below their ability levels on standardized exams. These researchers recommend the application of blue light — wavelengths that are largely absent in conventional lighting as provided by the sun — as a solution.