It is important to have the mind relaxed. "See the ball" is the "fine focus" that the great hitters use. The question is "how to slow the ball". In a game years ago against the "Greatest team in the History of Baseball" - Willie Mays All Stars.
Playing 1st base, I observed Henry Aaron and Ernie Banks, they each had the ability to "slow the ball" in their mind. Bonds looked for the red seams.
Bob