Can light induce stress? What’s the Sun got to do with vomiting? Why does blue light contribute to weight gain? What are the repercussions of disruptions in our circadian rhythms? And what does a doctor “prescribe” light for? It has long been known that light plays a very important role in human life. It is visible in the rich history of lighting development, showcasing the steadfast determination with which people have sought to bring light into their homes. Starting from prehistoric fires and torches, through candles, oil lamps, gas lamps, then the light bulb, neon lamp, halogen lamp, to finally stop at the LED lamp. But does technological progress align with a positive impact on human well-being?