Sunlight has coexisted with human bodies for thousands of years. Incandescent bulbs have been around for over a century. But LEDs are a much newer invention, having been around for less than a hundred years, with widespread use only appearing within the past few decades. The spectrum of electromagnetic radiation, of which visual light is a part of, extends to forms of radiation that are harmful and well known to be so, including gamma radiation and x-rays.
The LED market suffers from a lack of regulation and testing, allowing manufacturers to issue light bulbs that emit frequencies much higher than safe for the human body. View the graphic below for information on the types of light emitted by different sources. LEDs, even “white”, emit far more high-energy blue light than incandescents and sunlight. This form of light is not natural, and due to its higher energy, is able to penetrate through the human body.
Limited research had been conducted so far, but even with the limited research available, it has been found that LEDs are more harmful than other types of light. It is important to note that blue light is the shortest wavelength of visible light, which means a high level of blue light could be just the tip of the iceberg, with other forms of invisible radiation also being potentially emitted but not tested for.
Emission spectra of different light sources: (a) incandescent tungsten light bulb; (b) fluorescent white light bulb; (c) energy efficient light bulb; (d) white LED light bulb; (e) blue LED light bulb; (f) black LED light bulb; (g) morning sunlight; (h) midday sunlight; (i) sunlight at sunset; and (j) comparison of sunlight at midday (red), morning (yellow) and at sunset (green).