The reason for having each eye done seperately was that that was the protocol that the surgeon followed. He never did both eyes at the same time.
The reason for having each eye optimised for distance viewing was that I now only require to wear glasses for reading, since my distance vision is now slightly better than 6/6. There is no guarantee that you would obtain the same result and it is possible that you may have to wear glasses for distance as well. I suspect that with different corrections in each eye you would have to wear glasses all of the time since one eye would require distance correction and the other near vision correction.