Actually - DON'T peek, it'll ruin your scan. Instead of the crappy old curved hood, get and old cap and staple and staple a folded piece of cardboard (I used the A4 cardboaed cover off the a flight plan pad in those days), so that your vision is restriced left and above, but not right.
This minimises your head turning during scans to the right side of the panel, a mere swivel of the eyeball is all that is needed - ergo - less vertigo!