I’m starting to experience the same effects of eye pain and muscle tension with lamps. What I’ve noticed is that it’s not a problem with the bulbs but rather with the lamps themselves.
I bought two bedside lamps for less than €30 for both at a low-end furniture store (Conforama), one using E14 bulbs and the other E27. Both of them immediately trigger the same symptoms as if I had a screen in my field of vision—perhaps even more intensely. I’ve tested different LED bulbs with color temperatures ranging from 2800K to 4500K, as well as old-generation CCFL bulbs. Unfortunately, I haven’t been able to find incandescent bulbs to test. But no matter the type of bulb, these two lamps in particular always cause symptoms, even when using bulbs that I normally have in other lamps at home for hours without any issues.
There’s nothing in their technical specifications to suggest they use a different technology. Any electronic device in Europe operates on 230V 50Hz, and these two lamps have no notable differences compared to the other lamps I use at home.
I experienced the same problems during the Christmas holidays. I stayed in several Airbnbs where some lamps caused issues while others did not.
Another extremely puzzling fact: some time ago, I bought an Epson EcoTank ET-2850 printer, which works with ink refill bottles. The cost per printed page is supposed to be lower than that of a laser printer. But strangely, when I print a page with this printer, I experience the same symptoms while reading it as I do when reading from a screen. Even more bizarre, when I use the built-in scanner on this printer with my old Mac—which normally suits me fine—the scanned document causes symptoms when viewed on my own screen, which otherwise doesn’t cause me any discomfort.
I don’t understand at all. This makes no sense.