Non-invasive Brain Stimulation for Treating Symptomatic Convergence Insufficiency

Inclusion Criteria: * Best-corrected visual acuity of \> 20/25 in each eye at distance and near * Exophoria at near at least 4∆ greater than at far * Receded near point of convergence of \> 6 cm break * Insufficient positive fusional vergence at near (\< 15∆ base-out blur or break) * CISS score of 16 and greater for children or 21 and greater for adults * Have had a dilated fundus examination within the last 12 months * Informed consent and willingness to participate in the study and be randomized Exclusion Criteria: * Previously treated for convergence insufficiency with home- or office-based vergence/accommodative therapy * Amblyopia (\> 2-line difference in best-corrected visual acuity between the two eyes) * Constant strabismus * History of strabismus surgery * Convergence insufficiency secondary to acquired brain injury or neurological disorder * Manifest or latent nystagmus * Systemic disease known to affect accommodation, vergence, and ocular motility including multiple sclerosis, Graves disease, myasthenia gravis, Parkinson's disease, cerebral palsy, and diabetes * Developmental disability, attention deficit hyperactivity disorder (ADHD), learning disability or cognitive dysfunction that would interfere with treatment * Taking medications that can affect normal neurological function including antipsychotics, antiepileptics, and opioids * Presence of metal or electronic implants in or on the body, including pacemakers