refocus
To aim your attention back on something important again.
To refocus means to direct your attention or effort toward something again, especially after being distracted or after realizing you need a different approach. When you're reading a book and your mind starts wandering to what's for dinner, you have to refocus on the page in front of you. When a soccer team is losing at halftime, the coach might tell them to refocus on defense instead of trying to score so many goals.
Sometimes refocusing means getting back to what you were doing. Other times it means shifting your concentration to something new that matters more. A photographer refocuses her camera when the first picture comes out blurry. A student working on a big project might need to refocus after spring break to finish strong.
People often need to refocus when they feel scattered or overwhelmed. If you're trying to do homework while texting friends and watching videos, you might accomplish more by refocusing entirely on homework for thirty minutes, then taking a real break. The ability to refocus when you've gotten off track is a valuable skill that helps you finish what you start.