Before adding bones for eye control make sure that the 3D cursor is directly in the middle of the eye by selecting the eye and pressing Shift+S and choosing Cursor->selection.

With the armature selected enter Edit Mode. Pressing Space->Add->Bone will add a bone to your armature.

Chose to rotate around the 3D cursor to that you can rotate your eye bone forward while keeping it directly in the center of the eye. Repeat the previous steps on the other eye.

Select the tip of both eye bones by holding Shift then extrude two new bones from the ends with E. With the tips of the two new bones selected press Shift+S to snap the 3D cursor to the middle point between the two.

Add a new bone in between the two eye bones with Space->Add->Bone.

Parent the second eye bones to the bone in the middle or the gaze bone by first selecting the child bone then hold Shift and select the parent bone. Press Ctrl+P and select “Keep Offset”. Do the same to connect the first eye bones to the head bone.

Select your bones one at a time and name them in the “Armature Bones Tab” of the edit buttons window. The first eye bones should be named eye.L and eye.R. The second eye bones should be names eyetarget.L and eyetarget.R and the gaze bone should be name gaze.

In Pose Mode select the first eye bone and click “Add Constraint” in the constraint tab and select “IK Solver” from the drop down list.

In the OB: field type the name of your armature more than likely it is named “Armature”. In the BO: field type the name of your eyetarget. Make sure your ChainLen: is set to 1. Repeat the process on the other eye bone.

Select the eye mesh then Shift select the eye bone and Press Ctrl+P to make the eye bone the parent of the eye mesh. Select “Bone” from the list and repeat the process on the other eye. Your eye controls are now complete.