Vascos,
From what I've seen, there are two keys here: keeping the eyes focused on the ball and controlling the movement of the upper body.
In some ways, keeping the eyes focused on the ball helps keep the upper body more centered. This centeredness can help control low point. However, from the limited research I've done on the eyes and my experience with tour pros, I'd say that a key distinction is understanding look vs see. Looking takes deep focus to zero in on one aspect. Seeing is a softer view where you can see a wider field with less detail.
In sports, see is better than look. If you look, it can create extra physical tension that disrupts fluid movement. So yes, putting too much effort into seeing the ball clearly could potentially limit some distance (and probably consistency too). But, you don't want your head moving all over the place, so trying to see the ball can be helpful for a beginning golfer.