In Oklahoma OD's can do RK, the old vision correction. But in general, ODs can not do surgery. That specalty you are refering to basically gives the OD extra training in how to best co-manage laser patients. At least that is what I understand.
But to the first question, money. Generally the specialties do not mean more money. In fact, a lot of the time if the OD just does his/her specialty, they will make less. That is because right now there is not very much, if any, inter refering among ODs. If there is a problem the OD is not comfortable treating, they refer off to an MD, very very rarly to a specalist OD. That is changing with more and more ODs going through the residancy programs. As of now, in most areas an OD can not survive being just a pediatric OD, or what ever specialty you want. So the OD practices mostly as a general OD with a special interest in their specalty. This is a double edge sword. This way the OD does make more money and see more patients, but also limits the referals. What general OD would refer to another OD who is also a generalist. GPs don't refer to other GPs. That is like Walgrees refering people to Osco.
Times are changing, but it is slow. I DO plan to do a residance, what one, I don't know. As every forum on SDN always says, don't do it for the money. I want to do one because I think it will make me a better doctor.