Wondering whether the author has some kind of odd medical condition, and how common his experience is. The after-image symptom he describes is decidedly peculia

Wondering whether the author has some kind of odd medical condition, and how common his experience is. The after-image symptom he describes is decidedly peculiar. I can't say that I share his opinion. I find dark-mode preferable under pretty much all circumstances, and often find myself flinching when switching to a site with a fully white background.I also find it easier to read ebooks in dark mode when in full sunlight when reading on my tablet -- also the opposite of his preference. And I'm wondering whether perhaps he needs to turn down the brightness on his monitor.