Difference between Look at someone and Look on someone

look at someone—

1. direct one’s gaze towards smb.:

• “My God, look at these people! Just look at them—I ask you,” he exclaimed.

2. take a person as an example:

• Education is not necessary for success in life; look at your uncle Joe.

look on someone—regard smb. as a particular kind of person:

• Do you look on him as an authority on the subject?