So it all started out a few months ago last fall. I noticed that, even though I was wearing my glasses, white text on black in dark mode just didn't look quite as sharp as normal. Then an article came out saying that dark mode was problematic if you have astigmatism. Well BINGO! I happen to have a pretty bad case of astigmatism (one eye off by 1.75 diopters compared to the other one if I remember correctly) and only got glasses for it in August. Without glasses stuff is fuzzy and text is blurred/doubled, and glasses do help but dark mode still causes issues. I turned off dark mode on my cellphone and BOOM - the text was way clearer. Now don't get me wrong, I still use it when I am in extremely dark conditions combined with moderate screen dimming (excessive dimming combined with white theme annoys the hell out of me and makes my eyes feel weird likely due to the weird low duty cycle PWM dimming that AMOLED is notorious for). I also keep some individual apps in dark mode as their colorful UI is actually less readable with light mode or light mode affects readings of some sort due to the OLED consuming more power (Accubattery and Devcheck most notably). But using light mode actually makes long posts on Reddit, Android Central, and so on much much more readable. But of course this means that when I don't pre-set a device to dark mode (pretty much never do, LOL), I get blasted with white in pitch dark situations and have to change settings while being blinded.Not sure if it is connected to any of this, but I see halos around with logos on black screens on my OLED devices (especially my tablet).