Neural Implant

The bio-electrical interface between the patient's visual cortex and their VISOR. The devices were implanted bilaterally in the temporal regions of the patient's skull, and fed into the visual cortex. The external portion of the implant allowed for direct connection of the VISOR to the patient's head.

Geordi La Forge had two bilateral neural implants in the temporal regions of his skull that functioned as the bioelectrical interface between his visual cortex and his VISOR. A portion of his implants remained external to allow for the direct connection to his VISOR. By means of these implants, Romulans brainwashing La Forge were able to directly send images and secret commands to his visual cortex. (TNG: "The Mind's Eye")

Pholx mentions a neural implant Ensign Mayweather had removed saying that it may be the cause of his headache.(ENT: "Singularity")