<unk>  is the total or partial loss of vision in a normal-appearing eye caused by damage to the brain's occipital cortex.<unk>  can be acquired or congenital, and may also be transient in certain instances. Acquired<unk>  is most often caused by loss of blood flow to the occipital cortex from either unilateral or bilateral posterior cerebral artery blockage (ischemic stroke) and by cardiac surgery. In most cases, the complete loss of vision is not permanent and the patient may recover some of their vision<unk>  visual impairment). Congenital<unk>  is most often caused by perinatal ischemic stroke, encephalitis, and meningitis.
Rarely, a patient with acquired<unk>  may have little or no insight that they have lost vision, a phenomenon known as Anton–Babinski syndrome.<unk>  and<unk>  visual impairment (CVI), which refers to the partial loss of vision caused by<unk>  damage, are both classified as subsets of neurological visual impairment (NVI). NVI and its three subtypes—cortical<unk> ,<unk>  visual impairment, and delayed visual maturation—must be distinguished from ocular visual impairment in terms of their different etiologies and structural foci, the brain and the eye respectively. One diagnostic marker of this distinction is that the pupils of individuals with<unk>  will respond to light whereas those of individuals with ocular visual impairment will not.[citation needed]
Cortical blindness
Color blindness
Snow blindness
Computer vision syndrome
Aphasia
Cerebral atrophy
Cataract
Amblyopia