Can't see the full paper, just the abstract, but another thing I wondered if they took into account is the effect of strobing. They didn't include a control that doesn't strobe (such as halogen), since CFLs strobe in the kHz range. LEDs may or may not strobe depending on how they are driven and that isn't stated in the abstract.
It does however, seem much more likely that this is to do with extra energy in the UV end of the spectrum, which IIRC WW LEDs cut a lot more of (as well as the additional, visible blue light that makes CW seem so much brighter).
I can tell when LEDs are strobed at the (double) mains frequency; e.g. Christmas LED lights that likely blink at 120 Hz, since they don't have any electronics beside the LEDs. These do give me a slight nausea.
Compared to these, I can conclude that my home LED lights likely strobe in kHz range or above, or maybe not at all.
Cheap Christmas LEDs with no electronics look so awful because they strobe at 60Hz and are completely off for a full half-cycle (while the LEDs are reverse-biased).
I can't speak for you but I find the full-wave rectified ones not to be a problem. Of course the difference isn't just the doubled frequency, it's also a much higher duty cycle.
Oh wow, thanks for pointing that out. I thought I was having a migraine aura when I noticed vaguely flickering christmas lights out of the corner of my eye.
If the issue is confined to the uv, it's a dead-simple to fix. A uv-absorbant filter (ie like on all eyewear since the 80s) should eliminate the problem. Costs would be next to nothing. Conversely, anyone worried could don any eyeware, even swimming goggles have such coatings.
It does however, seem much more likely that this is to do with extra energy in the UV end of the spectrum, which IIRC WW LEDs cut a lot more of (as well as the additional, visible blue light that makes CW seem so much brighter).