Right Vs. Left
The relationships of the retinal fibers to the optic tracts are illustrated below, with the nasal retinal fibers in blue and the temporal retinal fibers in red.
| optic tract | temporal retinal fibers | nasal retinal fiber |
| left optic tract | from the left eye | from the right eye |
| right optic tract | from the right eye | from the left eye |
In split-brain patients who have undergone a corpus callosotomy (usually to treat severe epilepsy) the information from one optic tract does not get transmitted to both hemispheres. In carefully controlled experiments, split brain patients shown an image in his or her left left visual field (that is, the left half of what both eyes see), will be unable to vocally name what he or she has seen as the speech-control center is in the left brain hemisphere in most people. See the main article, split-brain.
Read more about this topic: Optic Tract
Famous quotes containing the word left:
“If we were left solely to the wordy wit of legislators in Congress for our guidance, uncorrected by the seasonable experience and the effectual complaints of the people, America would not long retain her rank among the nations.”
—Henry David Thoreau (1817–1862)