Across the United States, drivers are looking up at intersections and noticing a new, unfamiliar glow: small blue lights perched near traditional red, yellow and green signals. They are not decorative ...

Blue light usually comes from the sun but also from digital screens and LED lights. Some experts believe artificial sources may be causing eye damage in humans, but animal studies are inconclusive.

Those blue lights above traffic signals aren’t decorative. Here’s what they’re for and why more cities are installing them. Blue confirmation lights help police spot and enforce red-light violations ...

Blue lights on skin make it harder to see surface veins. As the “War on Drugs” declared by former President Nixon in the 1970s staggers on, science and governments look for novel ways to combat drug ...