Eye coordination is easily tested by looking down a string with a bead or a paperclip placed somewehere on the string.

Put on end of the string on the tip of yout nose and look at the bead or clip. You should see an "X" a "Y" or a "V" sometimes they appear upside down.

If the crossing point of the phantom string is behind the bead or in front of the bead then you have an eye corrdianation issue.