The light we see is as important for our health as the food we eat, the water we drink, and the air we breathe. For most of human existence, our ancestors lived with the natural 24-hour light-dark cycle, spending each day in natural daylight and sleeping in the dark at night. But since the widespread introduction of electric light, more than 90% of our time is spent indoors, under unhealthful and human-unfriendly electric light, which disrupts our circadian clocks and greatly increases the risk of cancer, obesity, diabetes, heart disease, and hundreds of other diseases. Today's LED fixtures, light bulbs, and screens are designed to produce cheap light with little regard for human health. Like DDT and asbestos, they are dangerously flawed technologies. THE LIGHT DOCTOR reveals extensive scientific evidence establishing the risks of blue-rich artificial light at night. Furthermore, it provides the practical information you need to counteract these risks at home, and in workplaces, schools, hospitals, and senior care facilities. Here is how to find and install healthy light bulbs and fixtures for both residential and commercial spaces, how to obtain the lights you need for evening and night use versus daytime, and how to obtain energy-efficient light that is also safe and healthy. You will also learn which outdoor lights to install to avoid harmful effects on wildlife, another inadvertent consequence of the LED revolution.