All 3 Uses

focus
in
Out of My Mind
(Auto-generated)

I have to stay focused.
p. 177.7 *

focused = concentrating on the matter at hand
I paste on a blank look, focus on one wall, and pretend their questions are too hard for me to understand.†
p. 18.6
The whole article seems to be focused on you.†
p. 240.4

Definitions:

(1) (focus as in: Turn your focus to question #2.)
to direct attention or effort toward a single thing; or the ability to do so without getting distracted
(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.
(5) (meaning too rare to warrant focus)