Originally Posted by dealt_with
Movement is mainly detected by peripheral vision so don't look at anything in particular, when you're relaxed you have less tunnel vision so you can see the bigger picture more easily. Relax and you'll be able to see everything, if you focus on one thing you're missing everything else.
State of constant alertness without falling into a one fixed point of focal concentration.
For a guideline
or default though, yes, sternum.