Sory, but I think that your logic here is flawed. You are assuming that less light is less stressful. I don't believe that's the case.
Sorry I haven't been clearer. I'll try again.
Of course I don't mean that less light is less stressful
whatever the circumstances. If you're turning in for a bit of shut-eye, the less light the better. If one is performing a task, such as reading, one obviously needs
sufficient light for the task. Trying to read in poor lighting conditions can also be stressful.
If you have calibrated your monitor so that its maximum brightness has been significantly reduced, that is obviously a measure which will tend to significantly reduce eye strain whether reading black text on a white background or WOB.
A source of confusion here may be in the definitions of white and black. These are not absolute terms, but relative terms. In reality we simply have two shades of grey.
Perhaps we could rephrase the question. Is pale grey text on a dark grey background more stressful than dark grey text on a pale grey background? I'm suggesting the answer in part depends on the degree of paleness of the grey. Of course there are other factors which contribute to eye strain, such as glare and not wearing spectacles with an appropriate magnification, or not wearing spectacles at all when one should be, etc.
In order to draw sensible conclusions from such comparisons we should attempt to keep all other variables the same so that the same pale shade of grey is used in both cases, in one case for the text and in the other case for the background.
I can appreciate that an excessively bright shade of pale grey text, at say 400cdm on a dark grey background could be more stressful to read than a dark grey text on a much less pale grey background, at say 100cdm.
But, let me ask you which you would prefer, to spend long hours reading black text on a 400cdm white background, or long hours reading a 400cdm text on a black background?
Out of curiosity, I checked the brightness levels of the white text on the Luminous Landscape home page. In Photoshop the RGB reading was just 204,204,204, for the text, whereas the white background to the picture of the Hasselblad 500 in the article "A Synthesis of History, Technology, and Art -By Richard Sexton" is 255,255,255.
That white background around the camera appears excessively bright to my eyes, and I think it's appropriate that the white text is less bright. If one were to criticise the arrangement of WOB on LL, I would say that the white text could be an even darker shade of grey. This might be less stressful for slow readers.