You can use Visine after Lasik, but it not a very good idea. Visine works by constricting the blood vessels in your eye. The trouble is that after it wears off, the blood vessels may "rebound" and dilate more than they would without the Visine. In many ways this is like nicotine craving -- you ...
The only reason to remove an iris is to eradicate iris cancer. I have come across couple of patients in my clinic asking to change the colour of the eye by removing the iris. This is completely wrong and I am not sure where the idea of iris removal came from....