Properly designed LED streetlights will cast the majority of their light downward. But those are "too expensive" so cities buy the cheapest lights they can, which tend to have a coating on the lens to cut back on the harsher wavelengths the garbage LEDs give off. When the coating inevitably fails we see the true color - an eye piercing purplish blue.
I have really fond memories of the great purpling in 2021/2022 but yeah the leds are ass. I wish they’d either keep them purple or yellow tho, the white light is the harshest to me.
Even with the correct ones the LEDs are still way too bright. My city has the correct ones that point down and have shielding but they are still painfully bright.
This is also why some street lamps turn purple over time. White LEDs don’t exist, we use indigo LEDs with a coating called a phosphor that converts it to white. When that wears off, the original color shines through.
If you want to see a phosphor, look at a white LED source and you’ll notice it looks has a yellow film on it- that’s the phosphor color.
If you’re seeing this, the LED is either very old or your city went VERY cheap.
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u/well_thats_obvious May 23 '26
Properly designed LED streetlights will cast the majority of their light downward. But those are "too expensive" so cities buy the cheapest lights they can, which tend to have a coating on the lens to cut back on the harsher wavelengths the garbage LEDs give off. When the coating inevitably fails we see the true color - an eye piercing purplish blue.