Table 1. Eligibility and Exclusion Criteria.

Eligibility Criteria:

Age 9 to 17 years Best-corrected visual acuity of 20/25 or better in both eyes at distance and near Willingness to wear eyeglasses or contact lenses to correct refractive error, if necessary Exodeviation at near at least 4Δ greater than at far Insufficient positive fusional convergence (i.e., failing Sheard’s criterion (30) or ≤ 15Δ blur or break on positive fusional vergence testing using a prism bar) Receded near point of convergence of ≥ 6 cm break Appreciation of at least 500 seconds of arc on the forms part of the Randot Stereotest CI Symptom Survey score ≥ 16 Informed consent and willingness to participate in the study and be randomized

Exclusion Criteria

CI previously treated with pencil push-up therapy (more than 2 weeks of treatment). CI previously treated with home- or office-based VT/orthoptics Amblyopia (≥ 2 line difference in best-corrected visual acuity between the two eyes). Constant strabismus History of strabismus surgery High Refractive Error: Myopia ≥ 6.00D sphere (in any meridian), hyperopia ≥ 5.00D sphere (in any meridian), astigmatism ≥4.00D Anisometropia ≥ 2.0D spherical equivalent Prior refractive surgery Vertical heterophoria greater than 1Δ Systemic diseases known to affect accommodation, vergence and ocular motility such as: multiple sclerosis, Graves disease, myasthenia gravis, diabetes, Parkinson’s disease Accommodative amplitude <5 D in either eye as measured by the Donder’s push-up method Manifest or latent nystagmus Developmental disability, mental retardation, attention deficit hyperactivity disorder (ADHD), or learning disability diagnosis in children that in the investigator’s discretion would interfere with treatment Family or household member or sibling already enrolled in the CITT Family or household member of an eye care professional, ophthalmic technician, ophthalmology or optometry resident or optometry student CI secondary to acquired brain injury or any other neurological disorder