All 9 Uses of

focus
in
White: The Great Pursuit

What was much less in focus was his own reaction to her.†
Chpt 18 *

in focus = into a state where something can be seen clearly; or into a state where something has come into view

Dozens of well-known politicians were involved in getting out the protest, but the world's eyes were focused on this one man.†
Chpt 20

Carlos grabbed his binoculars, adjusted the focus, and studied the flames.†
Chpt 44

Definitions:

(1) (focus as in: Turn your focus to question #2.)
verb: to concentrate, look at, or pay attention to

noun: the act of concentration, or the ability to concentrate

(to concentrate is to direct attention or effort towards a single thing)
(2) (focus as in: The focus of our study is...)
where attention is concentrated or directed
(3) (focus as in: bring into focus; or out of focus)
a state where something has come into view or can be seen clearly; or an adjustment made to permit a clear view
(4) (focus as with technical usage)
technical usage typically involves some sense of center or concentration such as:
- physics — a point where things come together such as the point where light rays meet
- geometry — a fixed reference point (as of a parabola)
- geology — the point of origin of an earthquake
See a comprehensive dictionary for other less common meanings.