To improve ones hand eye coordination one has no shortcut but to practice. However the practice should utilize both your hand and eye in a coordinated manner and to do that there are number of simple exercises. The purpose of these exercises is to acquaint your hands to the signal sent by brain and train the brain to in time and promptly process the visual stimuli send by eyes. You can train yourself for this by online exercise available for free on the world wide web, video game are also one good source of training however I won't recommends it. One good exercise I would like to recommend is take 30 ball mark each ball with a letter or number, now ask someone to through at least two ball at you and at the same time call the number or letter of one of the two balls thrown at you. You have to catch the ball which is called out. You can make different levels of this exercise by increase the no of balls thrown at you, the speed at which they are thrown and taking balls of different sizes. Do let me know if it works for you.