A patient has an injury to the optic nerves,such that the branches of each optic nerve that normally cross to the opposite side of the brain at the optic chiasm are severed.The remaining branches,which do not cross to the other side of the brain,are intact.Which of the following best describes the effect of this injury on his vision?

Question

Quizplus · Accepted Answer

The optic nerves carry visual information from both eyes to the brain. At the optic chiasm, some of the optic nerve fibers cross to the opposite side of the brain, while others remain on the same side. In this scenario, the branches of each optic nerve that normally cross to the opposite side of the brain are severed, meaning that the brain only receives visual information from the same side of each eye. Therefore, each eye can now carry only information from half of the visual field. Choice A is incorrect as both eyes are affected in the injury, not just the left eye. Choice B is incorrect because information from both visual fields still enters the brain, but only from one side of each eye. Choice D is incorrect because the injury does not affect a specific portion of the retina, but rather the crossing of nerve fibers at the optic chiasm.

A Patient Has an Injury to the Optic Nerves,such That