Coming at this from a slightly different angle, I have recurrent headaches (present at some level most of the time, and severe for a few hours a most days). When I'm feeling OK, light mode and dark mode are basically equivalent - I _prefer_ light mode, but dark mode isn't a hindrance. When I have a severe headache, light mode is fine, whereas in dark mode I find myself losing my place often, and it's vaguely unpleasant to read in a somewhat undescribable way that just makes me want to look away. It's akin to the text being slightly blurred, even though visually it looks fine.

The only conclusion I can can draw from this is that it's going to differ for difference people, and options are good.