correspondence of the visual axes of the two eyes; equality in the tension of the vertical muscles of the two eyes.
isophoria(ī″sō-fō′rē-ă) [″ + phorein, to carry]
Equal tension of vertical muscles of each eye with visual lines in the same horizontal plane; absence of hyperphoria and hypophoria.
Constancy of the heterophoria in various directions of gaze. See heterophoria.