what is accomodative convergence

Accomodative Convergence  

    Convergence is induced by the act of accomodation as part of a near reflex.

      AC/A Ratio

    is the amount of convergence measured in prism diopter /unit diopter change in acc.

   Normal value is 4 to 5prisms

   A high AC/A ratio may cause excessive convergence and produce convergent squint.    A low AC/A ratio may cause divergent squint.