It's actually not something covert. It's a manufacturing quality problem wherein components fail and the units have to be replaced with better quality devices. However this purple light problem is real and is widespread in some communities.
If it hurts, the lamps may be putting out a lot of ultraviolet. Here's a test: have something that is fluorescent orange. If it appears bright orange at night under the lamp, that's a sure sign this is an LED lamp whose internal phosphor has failed and it lets dangerous UV from the diodes out. (UV causes fluorescent materials to glow and actually emit light.)
A white light LED works like this: the LED actually puts out ultraviolet at the core. The LED converts that to white light by having a phosphor coating around the emitter to do that, they operate just like a standard fluorescent tube light. In the street lights with a manufacturing defect, the coating degrades and lets purple and UV out. And that damages eyes.
This may be topnotch Chinese LED quality here, where they are shoddy just to save a penny.
If the light hurts your eyes at night, blueblocker glasses can stop the UV. They will look clear for ordinary light but they block UV wavelengths. Might be useful for a cop on night patrol.
This is especially concerning since you really can no longer purchase indecent lights. This older technology leaked into the infrared which we tolerate well. This new technology leaks into the toxic UV band
Household LEDs are of less concern because their power levels are far lower than street lights, hence home bulbs don't degrade to leak UV as fast. Street lights run so hot that they need heat sinks for the LED arrays. When they get really hot, over time it breaks down their phosphors. Home LED bulbs not so much, at least.
It's actually not something covert. It's a manufacturing quality problem wherein components fail and the units have to be replaced with better quality devices. However this purple light problem is real and is widespread in some communities.
If it hurts, the lamps may be putting out a lot of ultraviolet. Here's a test: have something that is fluorescent orange. If it appears bright orange at night under the lamp, that's a sure sign this is an LED lamp whose internal phosphor has failed and it lets dangerous UV from the diodes out. (UV causes fluorescent materials to glow and actually emit light.)
A white light LED works like this: the LED actually puts out ultraviolet at the core. The LED converts that to white light by having a phosphor coating around the emitter to do that, they operate just like a standard fluorescent tube light. In the street lights with a manufacturing defect, the coating degrades and lets purple and UV out. And that damages eyes.
This may be topnotch Chinese LED quality here, where they are shoddy just to save a penny.
If the light hurts your eyes at night, blueblocker glasses can stop the UV. They will look clear for ordinary light but they block UV wavelengths. Might be useful for a cop on night patrol.
This is especially concerning since you really can no longer purchase indecent lights. This older technology leaked into the infrared which we tolerate well. This new technology leaks into the toxic UV band
Household LEDs are of less concern because their power levels are far lower than street lights, hence home bulbs don't degrade to leak UV as fast. Street lights run so hot that they need heat sinks for the LED arrays. When they get really hot, over time it breaks down their phosphors. Home LED bulbs not so much, at least.