What is a vision friendly site. It is a site that does everything possible to reduce white backgrounds on a screen. This site does use white text on a black background for a better contrast,
If you truly have bad vision,as I do, and you are overly sensitive to a bright screeen you should turn on the Microsoft High Contrast setting in the Ease of use section of the Control Panel.
This video gives details. It is unfortunately done with High Contrass off so for me it is difficult to watch. I will try to remake it at some point with High Contrast on so it is less painful to watch.
If you use google Chrome you can add an extension that will make most pages open in dark mode. Go to chrome settings and select themes. Download a dark mode theme. You will have to activate the theme with the extensions widget at the top right of the screen.