cortical blindness
Complete or partial loss of vision due to bilateral damage to the primary visual cortex, despite normal eye and optic nerve function.
Full Definition
Cortical blindness results from bilateral damage to the occipital cortex, specifically areas V1 and surrounding visual association areas, while leaving the eyes, optic nerves, and subcortical visual pathways intact. Common causes include bilateral posterior cerebral artery strokes, cardiac arrest with hypoxic-ischemic injury, and certain toxic exposures. Patients may retain some primitive visual reflexes such as pupillary light responses and blink reflexes to threat, but demonstrate no conscious visual perception. Some patients may experience visual hallucinations or deny their blindness (Anton syndrome), making careful documentation of the examination crucial for accurate diagnosis.
Usage
Usage note: Two words, not hyphenated. Emphasize that eyes and optic nerves are normal.
In Context
- "The patient developed cortical blindness following bilateral occipital infarcts but retained normal pupillary reflexes." — Ophthalmologic consultation
- "Despite cortical blindness, the patient could navigate obstacles, suggesting preserved subcortical visual processing." — Neurological examination