ryans Flicker Alliance, or, Light Bulb Database which measures LED light flicker.
Peter Erwin as an electrical engineer has excellent website.
@ryans Thanks for the links! I’m familiar with these and link to Peter Erwin’s site on www.FlickerSense.org. The FlickerAlliance site is a good start and admirable effort, but this kind of site needs some modifications before it can approach being a way to find safe bulbs, even if we knew the difference between safe and unsafe flicker, mainly because the Opple meter unfortunately isn’t sensitive enough and can also give misleading risk reports, especially when its flicker calculations fail. And the IEEE “risk” chart it includes is highly misleading since it’s an outdated chart of risk of flicker visibility, not health risk - there is no health data yet for LED flicker at and above 100 Hz. I’ll be referencing the site when I post my data - I tested all of the lowest flicker Sylvania and Ikea bulbs from the site whose flicker in the waveform graphs was below the level of detection of the Opple meter, some down to 0.06% flicker, and they all trigger brain injury for me, although among these, the 40W 2700K Sylvanias take much longer to start symptoms than any of the others I tested from the site. It would be really helpful if someone with more capacity for screen time than I could use a much more sensitive meter than the Opple meter to post detailed flicker waveform data for a lot more LEDs, including detection of color flicker - it would make sense for manufacturers to be required to report to a centralized database. It seems that once you’re dealing with very low flicker, the flicker pattern becomes very important in terms of whether symptoms start, how quickly they start, and what form the symptoms take, at least for triggering concussion-like symptoms for me. For me, some seemingly safe LED bulbs have higher % flicker than some quickly injurious LEDs, but the patterns of 120hz flicker are quite different. An IEEE-like chart of %flicker vs. frequency probably won’t be sufficient to define safety since it doesn’t show flicker pattern. To figure out the difference between safe and unsafe flicker patterns generally, more waveform and health data, especially for other people too, will be needed. We’ll also need to know how flicker changes as bulbs warm up and as they age - some of the bulbs I’ve checked change after being on for several minutes. And so far I only have aging data for Waveform, which flicker more as they fail, but I’m concerned if this is a more general trend that would mean needing to regularly check LEDs with meters to identify bulbs with newly developed, dangerous flicker.