Seagull Probably comes down to how they are powered. If the LEDs are powered by a standard light bulb fitting that will take any type of bulb they will flicker. But, if they are driven by some purpose built LED power supply, with a proper AC-DC rectifier, they will not flicker.

Moved from My treatment progress and search for solutions

Interesting! Would that apply to fluorescent bulbs as well? Summarizing the thread I had opened and forgetting for a moment about the LEDs, I got rooms with fluorescent bulbs run at low power which drive me insane and other rooms where the same model of bulbs are run at higher power and give me no issues. I was changed the bulb color temperature in the office but the power could not be varied, and I still have fatigue and eyestrain / eye twitching. So it does not seem to be color temperature related.

      AGI

      I don't know, I'm not familiar with fluorescent bulbs. Perhaps your lower power fluorescents have less persistence, for some reason.

      I also don't know if any overhead light is installed with proper ACDC power bricks - but if your light fitting was something elaborate that might be the only way to do it. The reason normal household LEDs don't have proper AC-DC rectification comes down to space, then weight, then cost. But if you are installing something fancy, with the wiring hidden in the ceiling, decent rectification, and hence no flicker LEDs is achievable.

      • AGI replied to this.

          Seagull if you are installing something fancy, with the wiring hidden in the ceiling, decent rectification

          This is the case. The building is ~ 4 years old and was designed to use modern lighting.

          Seagull no flicker LEDs is achievable.

          What do you mean with no flicker? High enough to not be perceived? Do you have a figure of the magnitude?

          So you do not have problems with LED lighting, do you? Only with displays?

                AGI

                If you power an LED with DC there will be zero flicker.

                I can't use computer displays when the room is lit with household LED bulbs without discomfort. I'm fine with flourescents.

                    a month later

                    Seagull
                    I am totally the opposite. My eye get irritated from looking to the computer monitor if there is fluorescent light within meters. Now i replaced them with warm flicker free led and things going smooth.

                      I'm glad this is a current conversation. I started using a Xiaomi flicker free led desk lamp today, presumably using some form of dimming. The thing somehow gives me friggen migraines and nausea after minutes! I was so sure that a constant light source would be fine but it must be something to do with LED spectra as well. Funny thing is, the LED spectras i've seen online all look pretty smooth. Keen to see what you guys come up with over lighting.

                        Seanicus

                        I bet its not really flicker free, does it have a hefty laptop size power brick?

                        Have you seen the soundcard oscilloscope thread? the simplest photo diode iterations shown in that thread should be sufficient to test it. From my experience, testing lights for flicker is a lot easier than screens owing to the high lumen output.

                          a year later

                          What do people recommend as the safest bulbs/overhead lighting?

                            Quad43

                            Incandescent. 100%. It is true black body radiation, same as sunlight.

                            You can still buy incandescent bulbs, the ban was very limited to specifically standard service A19 bulbs. You can buy incandescent flood lights, B19 bulbs, A19 rough service bulbs, chandelier bulbs, etc.

                                Quad43

                                Even incandescents can bother me now if I’m hypersensitized. I really love my flicker-free A19 LEDs I bought this year from Waveform Lighting - those and some much older (now unavailable) Philips flicker-free LEDs are always comfortable, even over long time periods. Waveform seems to be slowly expanding their flicker-free options, with several A19 options and some T8 tubes that will be flicker-free with an appropriate ballast. They’re the only current flicker-free LED manufacturer that I know of in the US.

                                For incandescents, I find Edison bulbs to be more tolerable than normal incandescents. Of course, most Edison bulbs are pretty dim, but I recently purchased incandescent 60W Nalakuvara ST64 Edison bulbs to replace some standard incandescent 60W GE soft white A19s that had enough flicker to bother me a little when I was hypersensitized. The Nalakuvara bulbs are actually just about as bright as the GE bulbs and the color temperature is slightly warmer, but pretty close. They still have a small amount of flicker and I’m not sure how it would be if one used them for a long time period - these were just the best option I could find that work on an existing dimmer switch.

                                I find incandescent candelabra bulbs to be better than A19s for some reason.

                                For a “best” option, for me it’s the actually flicker-free LEDs hands down.

                                    jen

                                    Problem is there are no "flicker-free" mains-driven LEDs. Yes, they call it "flicker-free", but are in fact outright lying, adjusting the meaning of the word so it fits their definition and their products' flicker specs. It is great you found something that works for you but those companies advertising "flicker-free" actually scam those people who search for true zero flicker. Which you can only get by using batteries.

                                        [KM] The bulbs will be zero flicker if they are engineered to include a DC-DC controller circuit along with linear regulators in series with the LEDs to eliminate the mains 120/100 Hz fluctuation. There is a discussion of this topic in the IEEE 1789 flicker recommendations on page 12, section 5.1D, with the full requirements for zero flicker bulbs described at the end of the paragraph with citations.

                                        Waveform isn’t lying about making flicker-free A19 LED bulbs. Note that their Edison-style LEDs do flicker (as they indicate themselves on the website), I assume because there isn’t space for the correct circuitry inside a bulb of that open style.

                                        Other companies like Philips definitely are currently misleading the public by using “flicker-free” to only reference visible flicker. I’ve tried multiple current “flicker-free” LEDs from Philips and Sunco and they all flicker. Definitely marketing misrepresentation.

                                        Battery power isn’t a guarantee of flicker-free light either, though. For example, I have a battery-powered LED book light that seems like it’s probably flicker-free at full brightness, but it flickers (invisibly) when dimmed. I assume PWM is the dimming mechanism even though it’s a battery-powered light.

                                          Quad43

                                          Thanks so best = a19s?

                                          You’re welcome! If you want to try flicker-free LEDs, the A19 shape bulbs at Waveform that are the normal bulb style and labeled as “flicker-free” are the ones that are better than incandescents for me. I routinely use their 2700K 60W-equivalent bulbs, but they have other color options too. I saw that they recently added a 100W-equivalent option and a very low blue light bulb in their flicker-free line of products, which both sound interesting, but I haven’t tried them.

                                            Does anyone know what has become of the "violet chip" LEDs that had a few articles some years ago? They were supposed to be sold soon, but I haven't seen them in shelves yet. I imagine they could potentially be much better for some of us. As apart from flicker, spectrum might be another factor.

                                              KM

                                              They are on market already, but have a same issue, MTBF (Mean time between failures), i bought and using russian brand Remez. Check http://sunlikelamp.com/ or may be you'll find something like this at your online marketplace.

                                                Quad43

                                                Any online light bulb retailer will sell them. You can get them on Amazon as well. Just google "rough service incandescent light bulbs" and you will find them. They are expensive (IIRC around $7 a bulb) but they are rated to last 10,000 hours, which at 12 hours use a day is over 2 years, and in my experience they do hit that lifespan. They also sell 20,000 hour bulbs as well, I have not personally tried them

                                                You can also buy 40W and 60W chandelier bulbs with the standard size base, they are identical to the old standard A19 bulb in every way, except instead of being shaped like a round globe, it is shaped like an oblong candle flame shape.

                                                I can still find 60W incandescent flood lights at my local Target, who knows how long that will last though. I would suggest when you find a bulb that works for you, stock up on a lifetime supply. Better to spend a few hundred now and be set for life than risk some overzealous administration outright banning all incandescent bulbs at some point in the future. They have been a (pointless) target of environmental zealots for year and since the vast majority of people just don't care because it doesn't effect them, it's something that could easily be slipped by and leave us high and dry.

                                                    One also can buy halogen bulbs with A19 bases (chandelier too) instead of rough service incandescents.

                                                      Sunspark

                                                      I've had iffy results with halogens. Some are fine, some give me issues. I stick with incandescent for everything.

                                                          dev