Amblyopia or lazy eye is an important cause of monocular blindness and is associated with a 2.6 fold increase in the risk for bilateral visual impairment in adults However, amblyopia can usually be prevented through early detection and treatment. Treatment focuses on correcting the underlying cause of amblyopia (e.g., strabismus or unequal refractive error) and promoting the use of the amblyogenic eye (e.g., through patching of the other eye). Effectiveness of treatment decreases with age and is less successful after age 12 years . The overall prevalence of amblyopia among children aged 6 months to 6 years is 1% to 2%. In addition, the prevalence of amblyogenic risk factors among children in this age range is approximately 3% . Because amblyopia can usually be prevented with early intervention, preschool vision screening for the prevention of amblyopia is considered cost-effective .