The retina contains receptors sensitive to blue light, and stimulating them suppresses melatonin production: https://en.wikipedia.org/wiki/Intrinsically_photose

The retina contains receptors sensitive to blue light, and stimulating them suppresses melatonin production: https://en.wikipedia.org/wiki/Intrinsically_photosensitive_retinal_ganglion_cells https://en.wikipedia.org/wiki/Intrinsically_photosensitive_r... Other frequencies also suppress melatonin production, but less strongly. If you look at the progression of artificial lighting, from candles, to incandescent, to halogen incandescent, to fluorescent, to LED, each generation typically increases both the blue light production and the brightness. Such strongly blue spectrum isn't an essential feature of the technology, so I suspect that it's marketing driven because it looks more futuristic. Additionally, a lot of LED lighting flickers at frequencies that are visible when you move your eyes via the phantom array effect: https://en.wikipedia.org/wiki/Flicker_fusion_threshold#Visual_phenomena https://en.wikipedia.org/wiki/Flicker_fusion_threshold#Visua... I personally find this very annoying, but even if you don't consciously notice this it's something not found in nature, and I'm not aware of any long term safety studies. I'm very skeptical of these changes. Humans have a poor track record of predicting safety implications of new technology (eg. radioactive materials as health products, leaded gasoline, etc).