I'm finishing law school and my wife is in optometry school. From conversations with her and her med school friends, optomotery and med school are fairly similar in first year course subjects and load.
As far as I can tell, law school is much more relaxed than medical school, but my wife sees my course work and studies and insists its the opposite. So, the bottom line seams to be that it depends on what type of learner you are, your skills and your study habits.
I love not having to memorize details of biology, histology and anatomy and I got dizzy every time I saw the orgo materials she studied in pre-med. I also can't stand the sight of blood. On the flip side, she finds legal writing and reasoning to be convoluted and mystifying, and would dread the thought of being subjected to the socratic method in a classroom of 150 students.