I got invisilign because my orthodontist didn't get my bit correct as a child and my teeth were showing spaces. It took 2 years but my smile has improved and so has the health of my teeth. It's not easy wearing them 18-20 hours a day. Yes, that much.
We're only supposed to take them off for meals and brushing. It's a commitment. Oh yes, and at first your speech sounds like you have a mouth full of rocks.