Visual cortex
The visual cortex was a part of the cerebral cortex, which was a part of the brain.

When Romulans brainwashed Geordi La Forge in 2367, they connected him to a device that could send images directly to his visual cortex, thereby making it impossible for La Forge to look away. () 

In 2369, tampering by solanogen-based lifeforms caused elevated levels of serotonin to concentrate in the visual cortex and hippocampus of several crewmembers of the  . Doctor Beverly Crusher realized that this was caused by a neuro-sedative used by the aliens to sedate the victims they experimented on. ()

The same year, Doctor Julian Bashir performed a neural imaging scan to stimulate Chief O'Brien's visual cortex. ()

Soon after, Ty Kajada asked Bashir to run a retinal imaging scan on Rao Vantika's corpse to confirm there was no residual activity in the Kobliad's visual cortex. ()

In 2375, the Borg Queen re-enhanced Seven of Nine's visual cortex with Borg technology with the addition of a neuro-processing adjunct. ()

The same year, The Doctor found that a number of the ganglia in Chakotay's visual cortex were hyperactive after a boxing simulation on the holodeck. This was due to the link between his mind and alien beings that lived in chaotic space. ()

External link
 
Brain anatomy