Update on Waveform lights (2700K and 3000K Centric Home)- they’re still ok for me if the bulbs are new, but they become highly toxic over time. They flicker more and more significantly over time until they fail completely by starting to blink on and off slowly. We put them in hallway fixtures in my apartment building so they were on 24/7 and after a few months I thought I must be imagining the bad effects as I walked down the stairs. They then started to be definitely toxic and I started looking for replacements. Around 7 months many were failing by visibly blinking. Coincidentally about that time I got both a $60 Opple meter and a professional UPRTek meter ($2500 meter for $800 used on eBay after waiting many months) and found dramatic flicker in the 7 month bulbs that weren’t visibly blinking yet and a bit more flicker in some 2-3 month bulbs than new bulbs. I’m putting data together for this and other lights to share - with you, the FDA, and connections in the engineering/scientific community, but the bottom line is that I’m fine with sunlight, candlelight, true constant DC LEDs (on simple battery circuits with no digital circuitry-controlled dimming), and seem to tolerate, rarely, extremely low flicker LEDs on AC power if the flicker pattern isn’t highly regular. Lots of LEDs that cause brain injury for me have flicker below what the Opple meter can detect (Opple can only detect to about 1% or so, but bulbs at least as low as 0.1% flicker can injure me). Opple can barely detect new Waveform bulb flicker - the pattern that repeats 120 times a second is quite complex/irregular within each 120th of a second, which may be why my brain can tolerate it when the bulbs are new. Unfortunately, an expensive professional flicker meter is necessary to detect the flicker of many harmful bulbs. The Opple meter is also tricky to use correctly as it flatlines artificially when the light is too bright and has too much noise when the light is too dim.
With engineers and other scientists in the US, we’re trying to correlate flicker waveforms with degrees of toxicity, but it’s complicated (and so far only using my data on myself). It seems like the flicker waveform itself is by far the major part of the issue for me, but maybe not the only factor. Incandescents are much less toxic than LEDs for me too, much less than their flicker waveforms alone would seem to suggest. And when I do get sick from incandescents (usually during the acute LED injury recovery period), the effects are different - common migraine typically that can be quickly stopped with ibuprofen, instead of my concussion-like LED symptoms. It’s not totally clear what the key difference is, but possibilities are (some/most??) LEDs have slightly flickering colors due to phosphor light emission/decay not being completely in sync with the diode light or other phosphors, and incandescent flicker is mainly in the red/IR range, which might have different biological effects than LED flicker which has low red and almost no near IR/IR. There’s interesting tangential research in the literature on led therapy through tissue that shows various biological effects specific to the color and sometimes pulsing of light that may be relevant.
Flicker meters, as currently designed, don’t measure color flicker. I’m using a portable UPRTek meter on a tripod, whenever possible, as hand-held readings aren’t stable enough unless the flicker’s really bad. I’m using camera color filters positioned over the meter to detect differences in color flicker. I have a lot of filters, but the most useful ones are the color-separating set of Wratten filters (Red 25, Green 58, and Blue 47), which I purchased as Tiffen glass camera filters that also fit my DSLR camera. The UPRTek data gives good enough data in excel files for analysis. I can also get good photos with and without the filters of those horribly toxic color-tunable LED bulbs by taking panning shots with the DSLR.
Currently I try to only use sunlight during the day and at night I minimize the use of AC lights and, especially if I’m recovering from LED brain injury, try to mostly use candlelight and battery-powered LEDs - simple AA or AAA powered string lights put inside mason jars with diffusing liners like parchment paper. The diffuser is necessary to eliminate the little tingle of pain from looking right at the LEDs - I think they may feel too bright in an otherwise dark room (cooler light worse than warmer light), but this doesn’t seem to be triggering of brain injury for me. I’ve screened incandescents and am using the lowest flicker ones I could find or newish Waveform bulbs or some very low flicker 40W Sylvania bulbs when I need more light - trying to figure out which of those is the least harmful… currently leaning toward the incandescents for limited use, but I’m not sure….
Beware battery-powered LEDs with dimmers - one of my worst brain zaps came from a dimmed battery LED lamp - flickering much faster than my phone could detect on slo mo, but in a complex, unique pattern - at least 40000 peaks per second but the peak amplitudes varied in slower periodic patterns. We really need to see flicker waveforms and not rely on calculated flicker metrics or just phone slo mo videos to keep ourselves safe.
If anyone else is able to collect and would like to contribute data linking flicker waveforms to symptoms or lack of symptoms, you can share it with the FDA Office of Radiological Health. If you’d like to share it with the US engineers and scientists starting to analyze my data please DM me - especially if you can collect high-sensitivity data in Excel files with a professional meter.
Also, everyone, please report health issues to the FDA if you haven’t yet done so -[https://ledstrain.org/d/1798-how-to-report-health-problems-with-led-lights-or-screens]