1. Play cricket. No matter how complicated and scientific we get about hand-eye coordination, the best way to improve it is to play and practice as much cricket as you can. This also includes practice drills with catching cradles and nets to help.
2. Play other sports. Games like hockey, golf or table tennis are all great ways to get your eyes and hands working together.
3. Play computer games. Im not a big fan of sitting around playing the Playstation, but you can't train all the time so you might as well get better while you relax right?
4. Get a reactor ball. Reactor balls bounce off the floor in strange directions so pick one up and find a mate to do some fielding or batting with. You can try catching it on the rebound from walls or batting with it.
5. Shrink your kit. You can get smaller bats and balls to drill with. Bradman used a stump and cricket ball. Although only use this kind of drill as a variation so as not to adapt too much and lose cricket skills.

Peak Performance have more on the science behind sports vision if you are interested.

Picture from Forfarshire CC