What is cortical vision impairment (cvi)?

Pbm in brain not eye: The term cortical vision impairment implys that there is a problem with the brain cortex (outer cell layer) that interprets the imput of the eye and visual nerve inputs.This is similar to having a good video camera, cables and system but the no screen to display the input in a way you can understand it.

Vision loss centrall: Your eyes send signals of vision to the occipital cortex at the back of the brain which is the computer that processes this and gives you this magic image called vision. If there is damage to this cortex (trauma, bleeding, stroke), then the vision diminishes the extent of loss due to the size of the damage. This is cortical vision impairment.