My goal is not to oppose the use of all LED lights, but only to focus attention on the necessity of producing and using safe LED lights that are completely free of flicker. LED light bulbs can be engineered either to flicker or not to flicker. Several years ago, both types were commonly sold.
Unfortunately, major lighting manufacturers seem to have shifted in the past few years to relax flicker guidelines and to only produce LEDs with significant flicker. These changes might have been adopted because of a slight cooling of color if LED bulbs are dimmed in a flicker-free way or because of a slight reduction in energy efficiency for flicker-free bulbs. At the same time, shifts in the past few years in how lighting manufacturers define "flicker," use the term "flicker-free," or refer to flicker metrics have had the effect of hiding from both consumers and from lighting consultants how much flicker is actually produced by particular LED light bulbs or more complex commercial LED lighting systems. Currently in 2021, with a few rare exceptions, there isn't a clear way to find LED lighting products that are completely free of all flicker even if one is looking for them, and many products currently marketed as "flicker-free" are not actually flicker-free at all.
A lack of research on the biological effects of LED flicker has allowed this trend to occur and makes it difficult for affected patients to advocate for change or even to argue that LED flicker is affecting their health. The extreme difficulty that individuals and businesses have in finding completely flicker-free LEDs in today’s marketplace makes the need for research even more urgent. Even essential services like grocery stores, doctor's offices, and schools are now unwittingly adopting flickering LEDs, which may significantly harm the health of sensitive individuals or deny access to food, healthcare, or education.
I am asking for the help of the medical and scientific community to evaluate the biological effects of the LED light flicker that is becoming increasingly ubiquitous in society. The public health impact may be widespread, based on extrapolating from related evidence, as LED flicker may not only harm sensitive individuals, but may also reduce the ability of children to learn in general.