The phrase 'focus for long' is not correct in written English.
You could, however, use the phrase 'focus long' or the phrase 'maintain focus'. For example, "It's difficult to maintain focus over a long period of time."
Even magazines often failed to hold his focus for long enough.
The other is an ability to delve deeply into a project or topic and focus for long stretches.
One reason is that in the land of attention-deficit disorder the media cannot sustain its focus for long.
One gets the feeling it was partly a matter of concentration; Keaton couldn't focus for long enough to stay in pressurised relationships.
And acknowledging this might allow us to recover a reason to read novels that doesn't depend on their supposed ability to make our brains focus for long periods of time.
What Mozart had, we now believe, was the same thing Tiger Woods had — the ability to focus for long periods of time and a father intent on improving his skills.
I've lived in many of the world's major cities and remote areas of Southeast Asia and it has been an invaluable experience that has become a strong influence in the way I shoot and go about determining my focus for long-term projects.
"Kids who can't concentrate on anything else suddenly stay focused for long periods of time".
Either way, it's better to work highly focused for short periods of time, with breaks in between, than to be partially focused for long periods of time.
Similarly, I can create into the evening, focusing for long periods without getting tired.
Focusing for long periods of time can be taxing on your system, and may result in mild to moderate headaches from time to time.
