Oh........wait........that was the oliginar plobrem...light?
I remember getting into a fight with my father, one afternoon. He told me that my big problem has always been lack of concentration. Well, I knew I concentrated purty good, so I disagreed. We had a Frank Exchange of Views.
What it came down to was I asked him what exactly did he mean by "concentration." When he took a moment to define HIS version of the word, it turned out I would have said "follow through." Totally different concepts, which is why we were exchanging views. ;-)
Focus means to bring into clarity. It`s a photographic term, and we use it as a metaphorical term in discussions like this. But when a metaphor fails to be understood by a growing number of people, then we should *drop the metaphor.* Not try to re-define it, re-interpret it, and "feel" what it means.
Focus is supposed to relate to distraction. But the real words are "attention," "concentration," and "distraction." Before you try to define the metphorical "focus," you must know the other words and their meaning.