Check out Dr Jack Kruse to get the full scoop! LEDs are blue light only this is like processed sugar but in light form. Incandescent light bulbs have a full spectrum of light, like a whole food, specifically they produce Infrared light which is a nutrient for the body. They’re technically “less efficient” because LEDS flicker and produce only blue light making them “more efficient”. Sunlight and darkness are the best light nutrients for the body all and all.