The sensation you are referring to is a latent sensory response between the eyes and the vestibular network. This phenomenon often occurs while under certain medications, particularly selective serotonin reuptake inhibitors such as Paxil. In the absence of medications, the same sensation has been described in persons suffering from sleep deprivation.
The actual sensation is fairly difficult to describe initially because of its transience, lasting but a brief instant and feels to some like a pulsing sensation, a zap or electrical shock or jolt in the brain. To demonstrate that it is actually sensory in nature, you can temporarily extinguish the sensation by forcefully looking both extreme left and right until the sensation is no longer triggered. Waiting momentarily and then looking to extreme gaze once again will reconstitute the sensation.
It is not a clinical sign of neurological disease, but rather merely a latent sensory response that becomes amplified. The oculovestibular network is responsible for sending signals to the brain regarding balance and orientation in physical space, so any disturbance can induce sensations of nausea similar to that experienced in motion sickness. Realize that when you look on extreme gaze in either direction, the signal and coordinated response with the vestibular network is increased as it would be when the body is in motion.
J Cottle, MD