Subjects with normal binocularity and have no vertical heterophoria did not exhibit increased vertical vergence amplitudes after training. Vision therapy for convergence excess. We conclude that VT is an acceptable option for treatment of CE, but more research is indicated for conclusive evidence. Convergence and divergence show large and sustained improvement after short isometric exercise. In two studies using push up and prism vergence exercises the conflict is shown to result from differences in the constancy of effort.
Improvement only occurs in exercises involving sustained effort in the direction being trained.
The effect of alternating movements in both directions is small and inconsistent. Substantial long lasting gains in either convergence or divergence prism vergence scores can result from just 5 min. of sustained effort at an angle halfway between the break and recovery points. The most likely physiological model involves potentiating processes that are specifically maximized by isometric exercise. Potentiation results in a positive feedback process, the effects of which are strong enough to precipitate strabismus and which might be deliberately manipulated in therapy of poor vergence control, if responses in the required direction can be induced. Click here to learn more about just who can benefit from vision therapy.