The influence of refractive correction upon disorders of vergence and accommodation.

Clinical care routinely includes prescription of lenses that compensate for the distance refractive error. Indeed, refractive correction is so commonly prescribed that we often neglect its potential effects on disorders of binocular vision. We report improvement of binocular function that resulted 1 or more months after prescription of an initial spectacle correction for 143 nonstrabismic patients who had a refractive error and either a vergence anomaly (28%), an accommodative anomaly (8%), or both (64%). Refractive correction was estimated objectively with an autorefractor and subjectively refined without cycloplegia. Most corrections were low to moderate in power, essentially following Orinda Study guidelines. Recovery of normal vergence and accommodative function varied according to refractive error type (79% of hyperopic astigmats recovered; 20% of myopes recovered), direction of astigmatic axes (67% recovered who had against-the-rule; 45% with with-the-rule recovered), age (63% below age 12 years recovered; 41% older than age 13 years recovered), and vergence anomaly (67% of patients with fusional vergence dysfunction recovered; 38% of those with basic exophoria recovered). These results suggest that improvement in acuity is not the only reason for prescription of a refractive correction--prescription of even small corrections should be considered as these can dramatically improve vergence and accommodative function for many patients.