I read the first and second paragraphs of this article while frowning. Understandably, the matter of lighting standards or the use of appropriate lights in a room, this is somewhat complicated to be understood by people like me, because it does not focus on things that are very technical, let alone ignore this problem.

I tried to keep reading the next paragraph, and I felt I was attending a seminar. I managed to read this article until the last paragraph (ending). The result, now at least I already know how the standard lighting the room.

However, about the formula described, I need to read it several times because the calculations are very technical. But, it is a challenge to be able to understand it maximally.

Thank you very much @kharrazi has illuminate my knowledge with an article about lighting.