Bridging the clinical–functional divide: Toward an actionable definition of childhood visual impairment

Clinicians and rehabilitation specialists frequently encounter a confusing gap between formal ophthalmological assessment summaries and the real-world reports of parents and educators regarding a child's visual function in familiar environments. This discrepancy leaves those designing treatment plans and environmental adaptations with more questions than answers. Bridging this divide requires pooling diverse assessment sources, integrating both empirical clinical metrics and structured observational data—to optimize a child's functional vision in daily life. The systematic overview by Micai et al.1 provides a timely, authoritative foundation to address this exact clinical challenge. The primary controversy highlighted by Micai et al.1 surrounds the historical, strict reliance on visual acuity thresholds (typically visual acuity worse than 6/12) in clinical, educational, and service eligibility frameworks. This narrow focus fails children with perceptual visual impairment and specifically those with cerebral visual impairment (CVI) who may retain intact visual fields and visual acuity better than 6/12, yet experience profound, debilitating lower- and higher-order visual processing dysfunctions. By evaluating children solely on ophthalmological measures, conventional frameworks risk excluding a substantial population from essential educational, clinical, and social services. Furthermore, for children with severe motor and neurodevelopmental disabilities, active visual acuity testing is extremely challenging, leaving their visual needs uncharacterized and not sufficiently addressed. While the need for a consensus definition for CVI has been identified previously,2 the overview by Micai et al.1 advances the field by proposing an actionable framework in their discussion. They characterize CVI as a lifelong condition marked by complex visual processing impairments resulting from brain injury rather than peripheral ocular pathology. This framing has profound, immediate implications for clinical practice, enabling a transition toward interdisciplinary, functional vision assessments that incorporate parent-reported questionnaires and real-time structured observations. Adopting Micai et al.'s1 multidimensional definition is a vital step toward ensuring that research, policy, and clinical care align to serve the real-world functional needs of children with CVI. Operationalizing this working definition globally and across disciplines will require future research to address three core priorities. First, the proposed CVI working definition requires rigorous empirical validation across diverse pediatric cohorts, alongside the development and standardization of psychometrically robust, child-centered functional assessment instruments. Second, longitudinal studies are urgently needed to determine whether early visual training, bimodal stimulation, and tailored environmental adaptations lead to sustained improvements in daily functioning, learning, and quality of life.3, 4 Finally, harmonizing this brain-based framework with existing World Health Organization classifications5 is essential to establish a unified, child-centered definition of visual impairment. This will ensure, first and foremost, a common language that fosters collaborative research and ultimately guarantees equitable service access across clinical, educational, and policy sectors. Not required.