Invisilign are clear braces for teeth. The system is based on clear, plastic trays made especially for you based on molds taken of your mouth. The way they work is that every other week you switch to a new tray. With each tray your teeth are adjusted a little bit. By the time you get to your last tray you have reached your goal.
I needed to get braces because a small gap between my two front teeth was getting bigger. My orthodontist recommended Invisilign Express. This is a six month procedure, rather than the one year program that regular Invisilign has. I've been wearing them for about six weeks and love them. My smile actually looks better already. You don't even know that you are wearing them except for the first day or two of a new tray. Even then, though, any discomfort is minor.
You can't eat while wearing them or drink anything other than water. But they pop in and out easily. If you need braces and they meet your personal needs, I'd say Invisilign is the way to go.