Binocular function score was determined in two participant groups (adult and child) with abnormal binocular vision from amblyopia or strabismus. None had co-existing general developmental, systemic or ocular pathology or congenital abnormality. Eligibility criteria in both groups were a history of strabismus (with or without amblyopia), or amblyopia (anisometropic, strabismic or combined mechanism). Amblyopia was defined as an inter-ocular difference in best-corrected visual acuity of 0.2 logMAR or worse.