Down in Timaru, New Zealand, a new LED street light outside a family home had some really bad effects on a resident. His father, an astronomer, did lighting tests over the next two years and made some interesting discoveries about blue light. https://i.stuff.co.nz/national/116865102/effects-of-led-streetlights-on-autistic-son-led-damien-mcnamara-on-dark-sky-campaign
(Score: 2) by GDX on Monday November 04 2019, @01:32PM
Most selection of led light is misled as normally only 2 and most 3 factor are take in account: power, color temperature and luminosity. There are 2 more factors that are also important: cri (color rendering index), and spectrum. (note, cri and color temperature can be derived from the spectrum comparing it to the one of an ideal black body, 100% cri ≈ ideal black body spectrum).
The problem lies in that most white leds lights have not very good cri with a spectrum that have unnatural blue peak at 460nm that is the worst for melatonin. Also the perceived luminosity also varies with the spectrum making that a 3000k and 4000k lights with the same lumems are perceived with different luminosity.
Most public lights are replaced only having the consideration of lumens and power but ignoring the color temperature, CRI and Perceived luminosity making the light uncomfortable bright in residential areas.
PD. I wish that a "perceived luminosity" rating was standardized and together with cri was mandatory in led lamps.