Cortical visual impairment (CVI) describes a type of partial blindness due to underlying injury to the brain’s visual processing centers. It is also known as cerebral or neurological visual impairment or cortical blindness.
A child with CVI has eyes that respond to light, a fact that underscores how the condition is not physically related to the structure of the eye itself. Instead, CVI is due to problems interpreting and processing visual information as it is received by the brain. In effect, children with CVI have eyes that can see, but the brain’s visual center has difficulty interpreting what is being seen. For example, they may have trouble recognizing faces (face “blindness”), interpreting facial expressions and drawings, perceiving depth, or distinguishing between background and foreground. They also have a preference for movement and are typically able to see objects better when in motion. They often have better peripheral vision than direct vision, leading to a lack of direct eye contact or “social gaze”.
CVI can be mild or severe and may fluctuate widely day-to-day, even minute-by-minute. Partial recovery is possible over time with treatment.
CVI is caused by any process which damages visual processing centers of the brain, especially to the occipital lobe (the back of the brain). Traumatic brain injury, epilepsy, hydrocephalus, lack of oxygen or blood flow to the brain, encephalitis, brain lesions, meningitis, and metabolic dysfunction are all possible causes of brain damage leading to CVI in young children and infants. CVI often goes undiagnosed because few medical professions are aware of it. If your child is exhibiting symptoms, it’s ideal to have both a neurologist and ophthalmologist examine her. A diagnosis of CVI can be made using MRI scans and possibly EEG, after determining that the child’s vision problem is not anatomical.