The Light Doctor: Using Visible and Invisible Light to Boost Health, Improve Sleep, and Live Longer

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 and the lack of near-infrared light during the day. Furthermore, it provides the practical information you need to counteract these risks at home, and in workplaces, schools, hospitals, and senior care facilities.

This 2nd edition of THE LIGHT DOCTOR expands the story to the invisible ultraviolet and infrared parts of the light spectrum which play a key role in our health. In our homes, workplaces and health care facilities we misguidedly filter out this invisible spectrum, depriving us of the full healing power of natural daylight.

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.

For over 40 years, Dr. Moore-Ede has been a leading world expert on circadian clocks and the health problems caused by electric light at night. As a professor at Harvard Medical School (1975 - 1998), he led the team that located the suprachiasmatic nucleus, the biological clock in the human brain that controls the timing of sleep and wake, and showed how it is synchronized by light. Since 2010, he has been the Director of the Circadian Lighting Research Center, which identified the key blue signal that synchronizes circadian clocks and developed patented LED lights, which provide health-optimized light across day and night based on comprehensive medical research. He has published over 160 scientific articles and authored ten books, including THE LIGHT DOCTOR, which was selected as a Best Book of 2025 by Kirkus Reviews. The second expanded edition of THE LIGHT DOCTOR: Using Visible and Invisible Light to Boost Health, Improve Sleep, and Live Longer has just been released.