What can be done to optimize legibility for white text on black backgrounds? [closed]

1. Which is better for the eyes a white background with black text a black background with white text or sepia mode?
2. Why do I struggle to read white text on black background?
3. Which is better white text on black background or black text on white background?

Which is better for the eyes a white background with black text a black background with white text or sepia mode?

The black text works better because black is also a color that doesn't reflect light in any part of the visible spectrum [source]. Therefore, fixating on black text while reading won't put as much stress on the user's eyes because it absorbs the light that hits each word.

Why do I struggle to read white text on black background?

People with dyslexia and astigmatism may have issues reading light text on dark backgrounds. For people with dyslexia, total contrast — white text on a black background, or vice-versa — can be difficult to read. Many dark themes use total contrast.

Which is better white text on black background or black text on white background?

From a specific focus on color in this research: “… The most readable color combination is black text on white background; overall, there is a stronger preference for any combination containing black […]