keep (one's) eye on the ball
To keep oneself very focused on something. Despite its wording, the phrase does not have to refer to baseball or another ball game. I graduated in just three years because I was able to keep my eye on the ball and prioritize my studies above all else.
keep your eye on the ball
If you keep your eye on the ball, you continue to pay close attention to what you are doing. She won widespread praise for her tough negotiating skills and her ability to keep her eye on the ball. Compare with take your eye off the ball.
keep your eye on (or take your eye off) the ball
keep (or fail to keep) your attention focused on the matter in hand.keep your eye on the ˈball
continue to give your attention to what is most important: We’ve got to keep our eye on the ball if we want to remain successful.