I have been reading about quiet eye in elite and sub-elite shooters. Quiet eye is defined as the final fixation, a tracking gaze or gaze behaviour observed immediately prior to movement in aiming tasks such as shooting. The research I was reading was written in 2010 and was, apparently, the first of its kind to explore the skill associated differences in shooting and how they could be related to eye movements and control of gun motion.
Interestingly, the quiet eye period was longer and happened earlier in elite shooters and the study also found a slower movement of the gun of elite shooters compared the sub-elite shooters. Stable gun motion, slower movement and a longer quiet eye duration are critical to expert shooting.
You can read all about it here; Quiet Eye Duration and Gun Motion in Elite Shotgun Shooting