Hand-eye co ordination is a very strange thing to practice. Of course, as a goalie, it is a very crucial aspect of being great at stopping pucks. A great way to train it is simply start standing in net and learn to react and predict to where the puck is going. But, for a more effective practice tool for this very peculiar skillset, you need something more... hands on.

The simple way is just throwing tennis balls at a wall very close to you and react to catching them. Preferably two at the same time, or have someone else throw them from behind you. Another good way to train this is something I learnt from my brother. Take something that weights less than a regular puck and dribble with it for 20-30 seconds very quickly. Never look down, just go for the feel of where you think it should be. This way, you learn how to not look at the puck and go more with feel, which will help in the long run to keep your head up.