Regarding LEDs
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The use of LED (solid state) lighting should be carefully selected to preserve a nighttime environment that protects the night sky, nature and ourselves.
Replace LEDs in key areas with incandescent light bulbs — While LEDs are indeed more energy efficient, the price you pay in terms of your health far outweigh such cost savings.
Avoid blue enriched light at night — Melatonin acts as a marker of your circadian phase or biological timing. Normally, your brain starts progressively increasing the hormone melatonin around 9 or 10 p.m., which makes you sleepy. Somewhere between 50 and 1,000 lux is the activation range within which light will begin to suppress melatonin production.
Turn off or dim all lights after sunset and avoid watching TV or using light emitting electronics for at least one hour before bedtime (ideally two hours or more).
After sundown, shift to a low-wattage bulb with yellow, orange or red light if you need illumination. A salt lamp illuminated by a 5-watt bulb is an ideal solution that will not interfere with your melatonin production.
If using a computer, smartphone or tablet, install blue light-blocking software like Iris, or use amber colored glasses that block blue light. Studies have confirmed that when using blue-blocking glasses, people produce as much melatonin as they do in dim light, even if they are in a lit room or using light emitting technology.
Sleep in darkness — Once it's time to go to sleep, make sure your bedroom is as dark as possible. Exposure to room light during sleep has been shown to suppress melatonin by more than 50 percent,17 but even a small amount of light can decrease your melatonin. Simply closing your eyes is not enough as light can penetrate your eyelids.