Hello veryevilfrost, Most sites use their own fonts, which might not be to your liking. Try this to see if it helps:

Go to: Menu -> Options -> General page under Language and Appearance select Advanced de-select -> Allow pages to choose their own fonts, instead of your selections above Select OK Refresh your tab(s)

Нет, это не решение моей проблемы. Ведь с текстом на страницах все в порядке в отличии от верхней панели, заголовков вкладок и прочих текстов непосредственно браузера.

Have you tried a high contrast Theme? https://addons.mozilla.org/en-US/firefox/search/?platform=windows&q=high%20contrast%20themes&recommended=true&type=extension

There are thousands of themes to choose from: https://addons.mozilla.org/en-US/firefox/themes/

Нет, темы не решают проблему. Текст остается не сглаженным.

See these threads about gfx.font_rendering.cleartype_params prefs:

• /questions/1251682 Firefox renders text incorrectly.
• /questions/1233884 Fonts not looking good on Firefox