White blue LED lights are harmful to human circadian rhythms and nocturnal wildlife.

“especially the white blue LEDs which are harmful to human body as well by changing our circadian rhythm”

Reducing nighttime illumination near observatories by using light shields saves money and preserves the ability to observe the stars.

“let's work together to reduce the nighttime illumination because it creates a sky glow and interferes with your ability to see the stars at night so they got together and all the street lights have these sort of caps on them so the light only points downward”