Artificial sunlight

This can be divided into five regions in increasing order of wavelengths:[1] It has been claimed that artificial light-sources whose spectra most closely mimic the spectrum of terrestrial sunlight are good for human health and productivity.

[2] Artificial sunlight is useful in treating and preventing seasonal affective disorder (also known as winter depression, which causes depression symptoms specifically in winter),[3] and delayed sleep phase syndrome, in which the circadian rhythm (the rhythmic alternation between daylight and nighttime behavior and bodily states) is disturbed and the person falls asleep much later than he or she wants.

The zooxanthellae require light to perform photosynthesis, and they provide the coral polyps with simple carbohydrates.

A technique employing light-emitting diodes (LEDs) allows microprocessor control of the parameters of lighting, such as warmth and coolness of color, which facilitates the simulation of daybreak, sunset, and lunar phases.

[7] Artificial sunlight (solar simulators) are also used for sun light exposure testing and of color fastness and material stability for textile, plastics and paints.