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Comment by JKCalhoun | Hacker News Reader

Interesting. Reading some of the comments they really run the gamut (no pun intended). It's reassuring to see though that people are starting to pay attention to this. For myself, it is the flicker (PWM) of some LED drivers that I am uncomfortable with. I went through a few different brands of LED track lights before finding one where I could perceive no flicker.

Similarly for LED lightning in the garage.

For the kitchen I had a need for rope lighting and never did find LED/driver combo that I was happy with.

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Here's a trick that I've found useful: If you have a phone that can do slow motion capture (I have a Pixel 2, but this also works with an iPhone), go to a Home Depot or Lowe's and take a slo-mo (240fps) video of the LED bulbs they have on display. Most flicker horribly on playback, including the expensive Cree bulbs.

The built-in LED spotlights that came with my house flicker like a rave concert whenever I capture a video in slo-mo. It's unsettling.

Phillips LEDs, especially the Scene Switch bulbs, are flicker-free according to my tests. Surprisingly, older CFL bulbs flicker much less than LEDs.

CFL stay semi lit between cycles

Former product display engineer here. Many of those light bulb displays are only meant to demonstrate color temperature, and have completely different power systems on board then an actual light bulb. Usually the AC rectification will be removed and replaced with a DC/DC converter.

This is mostly so that the display can be battery powered, because the availability of AC power on shelf is pretty hit or miss. I wouldn’t trust a display to indicate if the bulb has flicker or not.

The ones you're talking about demonstrate color temperature. The ones I've seen demonstrate the different light output of different brands and are connected to AC through a dimmer. You can play with the dimmer, and the price of the dimmer (each dimmer is different) and the bulb are displayed.

I can't imagine those are battery powered or that every different bulb on display has been modified.

This makes me wonder what the dimmer might be doing

Trying this at my house I don't see flicker from either my Philips warm glow bulbs, my Luminus Elite bulbs from Costco, or my Philips Hue lightstrips, but do see flicker with my Philips Hue A19 bulbs.

Great tip!

I was surprised to see flicker even on my $10 a bulb Soraa lights which are top of the line, cri 92+ bulbs.

Well, if its a light in your house, it is within your control. What if it is at work? In the public transport? On the street? In a grocery store? At a customer? If you suffer from LED strain, it'll hamper your ability to function in society. All this reminds me a bit of Chuck in Better Call Saul (portrayed by Michael McKean). Regardless of what he exactly had, the man was ill.

> Regardless of what he exactly had, the man was ill.

Psychologically. Jimmy clearly demonstrated that his symptoms were all in his head.

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