From The FAA Airplane Flying Handbook:
"The pilot should direct central vision at a shallow downward angle of from 10° to 15° toward the runway as the roundout/flare is initiated. Maintaining the same viewing angle causes the point of visual interception with the runway to move progressively rearward toward the pilot as the airplane loses altitude. This is an important visual cue in assessing the rate of altitude loss. Conversely, forward movement of the visual interception point will indicate an increase in altitude, and would mean that the pitch angle was increased too rapidly, resulting in an over flare."
In my experience, once the roundout and flare has begun, pilots are no longer scanning all around them (head on a swivel), but quite focused almost straight ahead.
I know I am.