<unk>  <unk>  is a form of visual<unk>  that is caused by a brain problem rather than an eye problem. (The latter is sometimes termed "ocular visual<unk> " when discussed in contrast to<unk> .) Some people have both<unk>  and a form of ocular visual<unk> .<unk>  is also sometimes known as<unk>  blindness, although most people with<unk>  are not totally blind. The term neurological visual<unk>  (NVI) covers both<unk>  and total<unk>  blindness. Delayed visual maturation, another form of NVI, is similar to<unk> , except the child's visual difficulties resolve in a few months. Though the vision of a person with<unk>  may change, it rarely if ever becomes totally normal. The major causes of<unk>  are as follows: asphyxia, hypoxia (a lack of sufficient oxygen in the body's blood cells), or ischemia (not enough blood supply to the brain), all of which may occur during the birth process; developmental brain defects; head injury; hydrocephalus (when the cerebrospinal fluid does not circulate properly around the brain, and collects in the head, putting pressure on the brain); a stroke involving the occipital lobe; and infections of the central nervous system, such as meningitis and encephalitis.
Cortical visual impairment
Visual pathway lesions
Cortical blindness
Dissociated sensory loss
Somatosensory disorder
Optic nerve hypoplasia
Sensory processing disorder
Congenital mirror movement disorder