Cortical blindness

May 2017


Definition


Cortical blindness is a condition characterized by bilateral blindness, i.e. the total lack of vision in both eyes. The patient is blind even though his eyes are in perfect health because there is in fact a lesion on the occipital cortex area of the brain, which is responsible for interpreting the information transmitted by the optic nerves. Cortical blindness is caused by brain lesions located at the occipital lobes, the centers of sight. It can be caused by a stroke in most cases, a brain injury, cerebral hemorrhaging or an infection such as meningitis or encephalitis.

Symptoms


Cortical blindness occurs with the following symptoms:
- usually a sudden disappearance of sight in both eyes;
- occasional visual hallucinations;
- amazing as it may seem, the patient may not be aware that he sees nothing: this is called visual agnosia;
- eyes are strictly normal visually, they are neither red nor painful;
- pupils are normal and continue to be reactive to light, contracting and expanding in reaction to light sources and darkness.

Diagnosis


The diagnosis of cortical blindness is strongly suspected in the context of sudden onset of vision loss in both eyes. The normal appearance of the eyes, the presence of reflexes and no abnormality in various examinations confirm the suspected diagnosis. The search for the cause is often the element that will confirm the diagnosis with the existence of a recent trauma. A brain CT, MRI, or magnetic resonance angiography will help underline any signs of stroke.

Treatment


There is no real cure to treat cortical blindness aside from treatments for the cause, if it is in fact curable. The recovery of sight can be rapid, gradual, partial, or even impossible in some cases.

Related

Original article published by . Translated by Jeff. Latest update on June 22, 2013 at 05:58 AM by Jeff.
This document, titled "Cortical blindness," is available under the Creative Commons license. Any copy, reuse, or modification of the content should be sufficiently credited to CCM Health (health.ccm.net).