Understanding What is a Visual Field
EyeMDs and Neurologist use visual fields to give us information about the nerves of the eye and the entire visual pathway. We can sometimes detect subtle nerve or brain changes or damage before a patient has any symptoms.
Understanding what your field of vision is exactly can be difficult to explain clearly or in the limited time one has with patients.
Below is a great video on what the visual field is and how it relates to the eye, the optic nerve, and it’s connection to the brain.
The later part about the LGN is likely more information than most patients need to understand.
http://www.sumanasinc.com/webcontent/animations/content/visualpathways.html
More information:
Great article: http://www.ajnr.org/content/28/1/3/T1.expansion.html
Localization of field defects and disorders of higher cortical visual function
| Field Defect or Syndrome | Localization |
|---|---|
| Unilateral central scotoma | Optic nerve |
| Bitemporal hemianopsia | Chiasm |
| Junctional defect (ipsilateral central scotoma and a contralateral superior temporal field cut) | Anterior chiasm |
| Central temporal scotomas | Posterior chiasm |
| Incongruous homonymous hemianopsia, afferent pupillary defect, and bow-tie atrophy | Optic tract |
| Homonymous sectoranopia | Lateral geniculate nucleus |
| Incongruous homonymous hemianopsia | Lateral geniculate nucleus |
| Homonymous upper quadrant defect “pie in the sky” | Temporal lobe |
| Homonymous defect, denser inferiorly | Parietal lobe |
| Gerstmann syndrome and a homonymous defect, denser inferiorly | Parietal lobe |
| Complete homonymous hemianopsia | Not well-localized |
| Homonymous upper quadrantanopsia with macular sparing | Occipital lobe (lower bank) |
| Homonymous lower quadrantanopsia with macular sparing | Occipital lobe (upper bank) |
| Isolated homonymous defect (macular sparing) without other neurologic findings | Occipital lobe |
| Anton syndrome (cortical blindness) | Bilateral occipital lobe lesions |
| Balint syndrome | Bilateral occipitoparietal lesions |
| Alexia without agraphia | Left occipital lobe and angular gyrus |
| Central achromatopsia | Bilateral occipito-temporal lesions |