Blindness and visual impairment.

The identification and treatment of children who have significant visual impairments are critical to their health and future well-being. "Legal blindness" occurs if a patient has central visual acuity of 20/200 or less in the better eye with corrective glasses or a visual field that is no greater than 20 degrees in the better eye. To determine eligibility for special education services, states must adopt a definition of visual impairment consistent with the Individuals with Disabilities Education Act (IDEA). For educational purposes, this includes students who have a visual disability that, even with correction, affects their educational performance adversely. The term includes both partially seeing and blind children.