I'm not necessarily asking you, but I'm taking your message as an opportunity to ask if anyone knows of an extension that does the opposite?

I have pretty bad astigmatism, and I cannot read pages with dark background. There used to be an extension I used for this purpose, but it stopped working several years ago, and I have suffered ever since. Going into developer mode to play around with the stylesheet works, but is a huge hassle.

Despite its name, that same extension does exactly that, I believe.

Actually, it has a switcher that lets you choose to darken or enlighten the webpages you read.

Honestly, I never understood why they had that option, but now I get it.