How Do I Turn on Dark Mode for Sensitive Eyes Without Lag

A flash of white before a dark theme kicks in is the main complaint from people with sensitive eyes.

No extension can promise it never happens, because extensions apply their styles while the page is loading. Modern Dark Mode adds its filter as soon as the page's HTML has loaded, which is quick on most sites, but you may still see a brief flash on some. Two things help: set Windows or macOS to dark mode, so sites that support dark themes load dark from the start, and keep your screen brightness low. Chrome also has an experimental "Auto Dark Mode for Web Contents" setting at chrome://flags/#enable-force-dark that darkens pages inside Chrome itself, though it's a test feature that can change or be removed.