1) Adjust the lens again 2) Dedicate oneself anew 3) Focus 4) Get back on track 5) Get back to the task at hand 
[v] - focus anew 2. [v] - focus anew 3. [v] - put again into focus or focus more sharply
refocus 1. To change or to adjust the focus of something; such as, a camera or a telescope. 2. To concentrate attention or efforts on something different.