In young children, vision is far and away the most important modality for the acquisition of knowledge; neural circuitry and brain development are tied to visual attentiveness, and the basis of intrigue and curiosity for a child are largely visual. In other words, beyond issues with simply not being able to see clearly, cognitive development is permanently compromised in some children with poor vision.
It has been well established in published literature that children who grow up not seeing well have lower achievement metrics; literacy rates, high school graduation rates and college attendance rates are significantly lower, as is employment and earning potential. Tragically, children growing up in poor, urban communities have much higher rates of vision problems: national reports estimate roughly 10-15% of school-age children have a vision issue (likely corrected with glasses) while isolated studies of urban centers have found upwards of 30-50% of children have a vision issue (likely corrected with glasses). While certainly multi-factorial, it is striking that these same children, in poor urban communities, are consistently underachieving in school with literacy rates that are significantly lower than more affluent community counterparts.
The public health challenge is that if most eye problems are detected early, much of the functional burden of vision impairment is preventable or reversible. Timely examination of people at greatest risk is thus necessary towards prevention. Towards this, the American Academy of Pediatrics and the US Preventative Task Force has issued policy statements recommending all children receive a vision assessment between the ages of 3 and 5, beginning in preschool and prior to the start of kindergarten. Further, it is recommended that school children have a vision evaluation every 1-2 years thereafter. Despite this recommendation, published reports claim less than 22% of all preschool children receive some type of vision screening; for those who do undergo vision screening and are found to have a potential problem, roughly 70% never actually follow up for formal evaluation and needed treatment; many sources cite lack of awareness of a problem at the level of the parents and affordability of and access to specialty care as contributing factors to this disparity.