“Keep your eyes on the ball.”
You're teaching your daughter to play softball. She's not very good at hitting the ball. You give her this advice.
Keep your eyes on the ball.
"Keep your eyes on the ball" is a common phrase from the game of baseball. It means to watch the ball carefully as it moves.
This phrase has also become a general piece of advice that means to focus on what you're doing. So someone might tell a coworker at work:
Don't worry about what people in other departments are doing. Just keep your eyes on the ball and get your work done.