Question

Larry goes to the doctor complaining that he can't see the right side of the visual field with either eye. Where in the visual signal-processing pathway is Larry's problem occurring?

Answer 1

This condition is called hemianopia. It may be caused by lesions in the eye, optic nerve or cerebral cortex. Under this condition there is an injury to the Optical Tract, which leaves half of each corresponding retina on the same side of the lesion without innervation.

If the problem is in the cerebral cortex, the problem happens in the left hemisphere of the brain since this is the one who controls the entire right part of the body

Answer 2

The correct answer is: damage to the left posterior brain or left optic radiation.

This condition characterized by the loss of half of the visual field on the same side (right side in this case) in both eyes is called homonymous hemianopsia. This happens because information from the optic nerves crosses to the other half of the brain via the optic chiasm (X shape).Since, the visual images from the right side travel from both eyes to the left side of the brain, it is most likely that the injury, tumor or trauma occurred on the left side of the brain. Stroke can also be the cause for the hemianopsia.