Objective Assessment of Disparity Vergence After Treatment of Symptomatic CI in Children

Inclusion Criteria: * CI Symptom Survey score ≥ 16 * Exophoria at near at least 4 greater than at far * Receded near point of convergence (NPC) of 6 cm break * Insufficient positive fusional vergence (PFV) at near (i.e., failing Sheard's criterion or PFV ≤15 base-out break) * Best-corrected distance visual acuity of 20/25 or better in each eye * Random dot stereopsis appreciation of 500 seconds of arc or better * Wearing appropriate refractive correction (spectacles of contact lenses) for at least 2 weeks prior to final determination of eligibility for any of the following uncorrected refractive errors (based on cycloplegic refraction within prior 12 months) * No use of BI prism or plus add at near for 2 weeks prior to study and for duration of study Exclusion Criteria: * Constant strabismus at distance or near * Esophoria of ≥ 2∆ at distance * Vertical heterophoria ≥ 2∆ at distance or near * ≥ 2 line interocular difference in best-corrected visual acuity * Near point of accommodation \>20 cm in either eye as measured by push-up method * Manifest or latent nystagmus * History of strabismus surgery or refractive surgery * CI associated with head trauma or known disease of the brain * Diseases known to affect accommodation, vergence, or ocular motility * Inability to comprehend and/or perform any study-related test