Excellente extension !

EN:
The best extension of its kind. Everything stated is there. Safe, open source and mozzila tested, updated regularly.

RU:
Лучшее расширение в своем роде. Всё заявленое есть. Безопасно, открыт исходный код и проверен mozzila, регулярно обновляется.

A great extension for the eye

Not always 100% on point when it comes to fonts in embedded frames (sometimes the font is greyed out and the background stay bright and shiny, also colours are sometimes darkened out or false) but that's rare and also highly depends on the code of a webpage. By far the best solution to work in low light atmosphere!