I am not sure if I would say a LOT of short breaks, but yes, we are on a quarter system so we have ten weeks of class, a week of finals then a week off.
The summer between 1st and 2nd year does not have any class, but there is an elective you can take where you "volunteer" in a nearby optometry office 1-2 days a week to see how private practice works. We have class each of the other summers. We usually get at least 1 week off for Christmas and a few days for Thanksgiving.
I hope that helps.