Cortical Vision Impairment (CVI) is a type of vision impairment caused by injury or damage to the brain (American Foundation for the Blind, 2016). This damage impacts the visual pathways and visual processing areas of the brain so that even though the eye may be able to see, the brain is unable to process, interpret or understand what it sees. Although ocular and neurological vision impairments can coexist, CVI is generally characterized by a normal (or close to normal) eye examination that does not explain the student’s vision needs, medical history that includes brain injury, and the presence of unique visual responses. According to Roman-Lantzy (2007, 2010), the degree of CVI can range from mild to severe and it is estimated that 30-40 % of children with vision impairment have CVI. The degree of CVI can range from mild to severe (American Printing House for the Blind, What is CVI?) (Roman-Lantzy, 2007).
Medical conditions known to cause visual pathway and visual processing damage are:
- Asphyxia and perinatal hypoxic-ischemic encephalopathy
- Cerebral vascular accident
- Periventricular leukomalacia
- Infection
- Structural abnormalities
- Chromosomal abnormalities
- Metabolic conditions
- Traumatic brain injury as known
(Roman-Lantzy, et. al., 2010.)
Unique visual responses or characteristics include:
- Light gazing
- Photophobia (light sensitive)
- Poor visual attention
- Color preference
- Restricted visual fields
- Difficulties discriminating or interpreting complex visual patterns, arrays and scenes
- Difficulties finding an object at a distance
- Better recognition of familiar objects than novel ones
- Attention to moving objects
- Looking away when reaching
- Visual latency (delay between visual stimulus and its perception by observer)
(Roman-Lantzy, et. al., 2010.)
For a more information on CVI, please see Christine Roman-Lantzy’s online courses at: http://www.perkinselearning.org/earn-credits/instructors/christine-roman-lantzy.