Stress
You will be responsible for the vision of people, young and old. Mothers, fathers, grandmothers, grandfathers. You'll operate on baby and toddler eyes. You could be responsible for whether a teenager lives a sighted life, or one in complete and utter darkness.
No pressure.
Yes, there is stress involved in this job. You could make a misdiagnosis and miss something that could have been prevented—something that causes loss of vision. You could slip up on the LASIK machine and blind someone (although it is very, very unlikely).
You might have your own practice and therefore have the stress of paying the bills, paying people's salaries, including your own and in bringing in new patients and keeping them happy.
That's why they pay you the big bucks. If you want a stress-free job, skip school and become an optician for fifteen bucks an hour.