take a look at how the word has evolved:

†1. intr. To look again or repeatedly at, to look back or meditate on, something. Obs.
†2. trans. To see or behold, to look at, again.
3. a. To look or read carefully over, with a view to improving or correcting.
b. To go over again, to re-examine, in order to improve or amend; †to condense by revision.
c. To go over (a subject already learnt) in preparation for an examination. Also absol.


so the study usage is in the sense of 'review'.