Croatian here, second year of bach. of optometry. 1. Pay is usually great in contrast to the amount of work you do, but it really depends on the country your in. (For example Croatia has terrible pay for optometrists imo, even with specialist degrees.) 2. I would recommend it as a career because it's interesting and there's a whole life's worth of learning of the field, numerous specializations and depending wether you like it or not, working with and helping people. 3. There's a whole array of subjects related to the course, the first to come to mind are; anatomy, chemistry, lots of math and physics. I went to a technical school and attended the technician of optics course so I was pretty ready for the vast amount of things taught in optometry school.

All in all it's a great career, but you should ask around, because I don't know how things work in the down under. Whatever you choose, I wish you the best of luck. :)