Well, we can visully distinguish few of the ice phases using the 3rd party softwars like VMD , PyMpl etc if not all. But it is not always desired to stress on naked eye that much to classify them. Even more importantly we will not be using our weakling eyes to conduct simulations along certain paths. So we have strong needs for order parameters. Order parameters are mathematical functions, which takes the attributes of the states and gives a scalar value, hopefully unique for each state available there.